Adrian Ulrich schrieb:
I see the problem, but perhaps something like a captcha would also be sufficient to prevent this.
It wouldn't prevent it, it just makes it harder. (Some spammers don't even use bots to create accounts. Using real people appears to be cheaper sometimes..)
It always takes time until you have enough evidence to close an account. First there have to be a couple of spam-runs which are identified as spam (and not just as some newsletters a couple of recievers forgot or weren't aware they ordered it) and then he will, of course, tell you his computer got hijacked etc. Besides that real spammers are normally people you simply don't want to get in contact with. They often answer with endless and pointless pseudo-legal argumentations and a lot of FUD. Even some threats are possible (like "we will watch what you write in the usenet" or "we see that your employer is doing something which might be illegal").
Regards Peter