Just punching a few letters into a search bar can give them access to a wealth of information you may or may not want them accessing.
There are many ways in which we can keep track of our kids' behaviour and protect their data. Together with the UK Safer Internet Centre we've created a guide to help you keep your children safe online.
Parental controls: activity monitoring
There are some great activity monitoring tools available that allow you to see which sites your kids are visiting, what they're searching for, and who they're talking to via instant messaging.
It may feel a little Big Brother, we know, but it can also act as a detterant if your kids know you have access to what they're looking at. It also means that should you see something you don't like the look of, you can have that conversation with them straight away.
For instance, KidLogger allows you to monitor your kids' activity from your mobile phone.
What else can I do?If you have a child who's particularly keen on technology and surfing the web, it might be a good idea to put in place some time limits for their usage. It's very rare, but some children's online life can take over their real one, and this can lead to all sorts of problems. Kids sitting up in bed ‘til the small hours is also going to leave them tired and grumpy.
It's likely that you're the one who's bought the phone/tablet/laptop etc so you'll have a chance to set some parental controls on it before you give it to them. The user manual should tell you how to do this. It's also worth searching online for other parents' tips for that particular device.
Remember, gaming devices have Internet access, so make sure you set parental controls on them too. As well as setting controls on the devices, make sure you've set them through your service provider (BT, Sky, Talk Talk, Virgin Media etc.) too.
Keeping all devices out of the kids' bedrooms, especially after they've gone to bed is a good idea. You could also set time limits for games consoles and apps. thinkuknow website has some really useful advice on how to speak to your children about websites they should and shouldn't visit.
AppsYou can get an app to do almost anything these days. Tell you the weather, take vintage-style photos, help you learn a new language, play games - the list really is endless! Some of them are free to download and others cost money. Some will also allow in-app purchasing. This is where a user will be asked, for example, if they want to buy more lives to continue the game or pay to get some extra features added to the app. You get apps from an app store, like Google App Store, Blackberry App World or Google Play.
The dangersIn-app purchasing is being made clearer now, but some children have made the headlines for accidentally running up huge bills (we're talking hundreds of £s!) on their, or their parents' phones or tablets.
The age range on apps, which is often supplied on the information before you choose to download, is only provided by the company that designed the app, it's not overseen by an external body. So your children may be downloading apps which aren't age appropriate.
If your children are using your phone or tablet, they may well stray from the game they are playing onto other areas of your device that you don't want them accessing.
What can you do?Make sure your kids don't have your password which might allow them to spend money while they are in an app. Better still, check out the policy of in-app purchases before you download the game. This information will be available for you at the app store. You can turn off in-app purchases and on some phones it's even possible to completely block them - check the settings on the phone to do this.
Over a third of 3-4 year-olds use the internet at home, so it's important to be on the ball from when they are really little. Check out the reviews of any app before you download it for your kids. This should give you a steer about what other parents think about it and whether or not they are old enough to use it.
With older children, discuss which apps they have and talk to them if you think any of them are inappropriate or could end up costing them a lot of money.
It might be a nice idea to suggest some apps for your children to download, then you can be sure you're happy with them. Check out these reviews for some ideas. Visit commonsensemedia.org/app-reviews.
The DangerBy posting personal information or pictures of themselves online, children can become the victims of cyber bullying, grooming, identity theft and blackmail.
What you can doSet up the account with your child so you can discuss the privacy settings and protecting their online date with them and make sure they fully understand that it is not a place to post pictures or comments that are in any way private.
Make sure their pictures can only be seen by their ‘friends' on Facebook, and that they never accept the friendship of someone they haven't met IN PERSON.
Set up your own account - even if you don't want to use it - so you can fully understand how it works.
Tell them the story of an American teacher who wanted to show her class how quickly a picture could spread online. Within a few weeks the picture was seen by nearly 1 million Facebook users. Ask your kids to think about that every time they post a picture - ‘would they be happy for a million people, including their parents, to see it?'
Teach your children how to block people and report things they find upsetting.
Make sure you sit down with your children and go through the Facebook check list to keep them safe.
CyberbullyingQuite simply, cyberbullying is bullying through the use of technology.
The dangersBeing able to contact someone by text, phone, email or chat room at any time of the day or night, has had the terrible side effect of a surge of cyber bullying.
Being able to hide behind a computer or a phone means cowardly bullies can target victims really easily, and often when they are at home and should be feeling safe.
What they can doAs with any form of bullying, it's important to let your children know they can talk to you about it. If they don't want to, encourage them to contact a bullying charity like BullyingUK.
You need to encourage them to keep all messages - however embarrassing or hurtful they may be - so there is proof of what's been going on.
Don't ban them from using their phone or computer. This might make your child feel more isolated and the internet is a great way for them to find help.
Tell your child not to reply to any nasty messages, however tempting. A bully is likely to be looking for a response, so make sure they don't get the satisfaction.
The dangersTwitter is quick and easy to use and its simplicity has led to lots of hot-headed celebrities and politicians saying things they've later come to regret. If adults have trouble thinking before they tweet, imagine the trouble kids can get themselves into!
It's also far easier to set up anonymous or multiple accounts than on Facebook, so bullies can hide and make their victim think it's more than one person ganging up on them.
Most of the posts on Twitter are public, so there's a danger of your kids giving out personal information by mistake.
What you can doTry to make your children understand that even though you can delete tweets, it only takes a second for someone to retweet their message and then there's no getting it back.
Explain to your children they should never retaliate to any abusive messages they receive, not to share any personal information or photos on Twitter and make sure they know how to block other users who they don't want following their tweets.
Twitter has a comprehensive guide for parents.
Mobile phones, sexting and intimate photosAs soon as a teenager or child gets a phone, it seems like they are permanently attached to it. (We can't pretend we're not slightly guilty of that too!). But it rarely seems like they ever talk on it, so what on earth are they doing?!
The dangersAs well as the possible problems with apps, email and the internet, which we've already talked about, there seems to be an alarming trend for children to send each other semi-naked or provocative pictures of themselves and sexually explicit text messages. The consequences of one of these pictures or text messages getting into the wrong hands or going viral could be devastating for any young person.
What you can doAll children are going to do things on the spur of the moment that they may regret later, so talk to them about how huge the fallout from a bad decision like this could be. They may trust someone not to show those pictures or texts to anyone else, but phones get lost and pinched and it would only take a few minutes for their reputation to be shattered.
A popular social networking site that lets people around the world (over the age of 13) ask and answer questions.
The dangersAsk.fm has been in the news for numerous stories of cyberbullying and the website's lack of regulation has caused lots of controversy.
Anyone on Ask.fm can view another user's profile and content, and the site also allows users to post questions anonymously. Therefore your kids could run the risk of giving out their personal details by mistake or leave themselves open to unwanted and anonymous comments or even cyberbullying.
What you can doThe best way to understand how Ask.fm works is to set up your own account. If you decide to let your child use the site go through the saftey tips and privacy settings with them - you can help to protect your child from unwanted posts by making sure they tick the boxes to block anonymous questions and stop their answers from showing up on the ‘Stream'.
Before you let your child loose on the site, explain to them that they should never share any personal information like their phone number or any private pictures, videos and comments as it's a risk to their data becoming compromised online.
Ask your child what they would do if they did receive an abusive comment and encourage them never to reply to such posts and to report them straight away.
Show your child how to blacklist or block any unwanted followers on the site.
Got something to add? We'd love to know your tips or tricks for keeping children safe online. Leave us a comment below!