I got another one of those fake Ebay "check-your-account" emails the other day. The technique's called phishing and, in short, it's basically an email with a link to a fake website made to look like Ebay, Paypal, or whatever. You're supposed to believe that your Ebay, Paypal (etc) account needs to be renewed so if you'll just be kind enough to follow the link and fill in your bank account details, you'll be up and running again in no time. Phishing is quite common, in my inbox at least, and a real pain.
For years, I've deleted these things without a second thought, but this time, I followed the link, entered a fake name, a fake bank account number, a fake PIN (as if Ebay would need it), a fake address, a fake city... you get the idea. The thing is, I went to some lengths to ensure that the information wasn't obviously made up, hoping that the fraud at the other end wouldn't immediately see what I was doing. And prayed to the net ghods that he would actually use the information to create a credit card, and attempt to use that card in an actual store.
Why not do the same the next time somebody sends you an email asking you to update your Ebay account? Make some trouble. See to it that these people are kept busy. I'm sure that sooner or later, somebody will try to use the information to make that fake credit card, and to try to use it. Just think of the fun you've created. It's not going to stop them all, but it's a start.