Sony has warned that its PlayStation Network, which has been down for a week, was brought down by hackers who may have obtained users' personal details - potentially including credit card information.

If you're a PSN user, how can you tell if you've been affected, what will be the consequences, and what should you do now?

1. Change your passwords

Do everything you can to minimise your exposure. Identity thieves are likely to have obtained PSN account passwords, so change yours right away.

And if you're one of the many web users who recycle passwords on various sites and services, remember to change the passwords of any other services where you've repeated your PSN one. This is particularly important on e-commerce sites where money or financial data changes hands.

2 Check your card statements

The potential credit card leak is your next priority. Check your statement online as soon as possible, and keep an eye on it in future for unexpected transactions. Contact your bank at once if you see anything untoward. They will investigate any suspected fraudulent activities.

3 Am I liable?

Victim of internet fraud should not be held liable for financial losses "unless the customer has acted fraudulently or with gross negligence", according to the Lending Code (pdf; see part 138). In other words, you're probably covered, but it's worth speaking to your bank to check their policies, and any steps they'd recommend.

4 Watch our for related scams

Email or phone details may have been leaked too, so PSN users should be even more wary than normal of telephone and mail scams in the coming months. The usual warnings apply: if an offer seems too good to be true, it probably isn't, and if you've won a competition you didn't enter, something's probably amiss. It sounds obvious, but people who rarely encounter fraudulent activity could easily be caught out if they are suddenly exposed to seasoned scammers.

5 Get your entertainment fix elsewhere, for now

Hopefully PSN will be back up soon, but in the mean time, turn to our round-up of some alternatives to PSN - we look at some online gaming options for PC users, and ways to download and stream media and movies without the PlayStation Network.