For those who don't know about Bitcoins, they are a digital currency. More about Bitcoins on Wikipedia here.
Whilst it doesn't sound much, the price per Bitcoin is roughly $212 so as you can see, the ransom has gone from just over $400 to just over $2,100. How much is your data worth? Maybe not that much you might think but I'd advise you to think again.
You might not think you have anything worth losing on your PC but wait until it's gone, then you'll realise how much you actually did have so get your stuff backed up off your PC now - before you lose it.
If you've already backed up your data, well done but remember to add all your new documents and photos as you go along so you don't get caught out.
Keep safe everyone.