If you're unhappy in your marriage then perhaps you should think twice before searching for 'good divorce lawyers' on the web.

And no matter how annoying the kids are being, don't type 'child-sized handcuffs' in the search box and press enter.

It's not that you won't find what you're looking for, but you can't be certain who else will know what's on your mind, as some customers of internet provider AOL found out recently.

In August they gave university researchers details of over twenty million separate searches made by 650,000 users over a three month period earlier this year.

And within minutes a lot of other people had got their hands on the same information.

AOL had given each user a different number, but didn't include any other personal information, so they thought that nobody would be able to figure out who was searching for what.

They were wrong.

Lots of people search for their own name or address, or, because they are from America, their social security number.

So within a couple of days Thelma Arnold, a 62-year-old woman living in Georgia, had been contacted by the papers because they had identified her from her searches.

Fortunately for her she was only looking at house prices, but a lot of other people had been searching for much more embarrassing things.

When AOL realised what a mistake they'd made they took the information off their website and the person responsible resigned.

But by then lots of copies had been made, and people were wondering just how much the search companies know about us all.

The answer, clearly, is that they know a lot. Google and other search companies keep a record of everything people are looking for, because they say it's useful to them in improving their results.

And because most search engines keep track of which computers are making which searches, they can link all the searches together.

This is a bit worrying. Once you're a regular internet user it's almost impossible to get by without using search engines like Google or BBC Search.

The chances of your personal search history being revealed are very small, but the companies who run the search engines can use the information in lots of ways.

And most of them are based in the USA, which doesn't have the same data protection laws that we have over here.

BBC News: AOL apology for search data error

Spend any time on a bus or train and you'll notice that we're all spending a lot more time listening to music on the move.

A lot of people have joined the white headphones brigade with an Apple iPod, but other music players, phones and even old-fashioned CD players are all out there.

And sometimes it's pretty loud. After all, if you can hear the 'chik-chikka-chik' of someone's music from across the aisle on the train, imagine what it's like inside their ears!

Now that there are lots of legitimate music downloading services we're all buying new songs with a single click.

And even new computer users are figuring out how to copy their CDs onto their computer.

In fact, whenever I put a music CD into my PC it asks me if I want to copy the music to iTunes, so I don't need to remember how it works!

But the Royal National Institute for the Deaf, RNID, is worried that we're going to have problems in future.

Especially as better battery life means that we can listen for hours and hours while on the move.

They've found that nearly three-fifths of 16 to 30-year-olds don't even know that there could be a problem from listening to music too loudly on their MP3 players.

And they have a campaign, 'Don't Lose the Music', to try to improve things.

They want manufacturers like Apple and Creative to put warnings on the players and their boxes, so at least they will have some idea of the risk.

Find out more at: Don't Lose The Music