I was told about a forums website that managed to block a user who had continously abused it by filling it with offending material. According to what I know, the abusive user was not connecting to the internet from a static ip address, and the block was not done using a cookie (and of course not based on the abuser's username on that website, which he registered each time anew using new fake oersonal details and free e-mail accounts). I know the abuser is not a computer expert, but certainly knowledgable enough to know how to get rid of cookies.
I am curious to know whether you have an idea how this could have been done. What additional ways could use to identify his personal computer? The only idea I had (and I don't know whether it is possible or legal) was that they managed to get some sort of trojan horse into his computer, but this seems far fetched.
