Thanks a lot softtouch2009, that makes sense. But what still confuses me is that my ISP was alerted by another person (the target site, I presume). They pasted the alert at the end of their message :
"Hello Abuse-Team, your Server with the IP: xx.xx.xx.xx has attacked one of our server/partner on the service: "regbot" on Time: Mon, 20 Jun 2011 22:21:16 0200 (...)"
How come someone else than my ISP could "see" my IP?
Well my guess would be one of your public proxies that was anonymous went transparent while you were posting. Meaning a public proxy is just a proxy that, in most cases, was left open by accident. Then those admins are getting the abuse reports. So they probably made the proxy transparent. (theory, I dunno).
But if your proxies were transparent they should have sent the abuse report to the IP of the proxy. Although I suppose they could check their proxy logs and forward it.
I only use your private proxy, and I have never had an issue. They just discard any "abuse" reports.
Abuse reports burn me up anyway, cause they use terminology like "attacked" out network. Yeah, we loaded a page on a public forum and registered. So what, make it a private forum if you don't want it.
I just spent time arguing with one of my hosting companies about this. Its not illegal and its not defined as spam in their TOS, but yet they call it spam. Basically its whimisical. Your ISP reserves the right to fire you as a customer if they want to. Why? Just because they get a complaint from someone.
Frankly you could make a business out of faking complaints to competitors hosting companies and ISPs and drive them crazy.
The great thing about my hosting company, is as it worked out I can just step over to the next company, and I am getting a better deal. Kind of a pain to move, but this new company is much more tollerant of abuse complaints. They just hit "delete" and move on, as it should be.
The problem with ISPs is there is usually only a couple to choose from. So you don't want to mess around. I got an abuse complaint for a blog comment from scrapebox way back when I first started messing with it, noob mistake. I only have 2 ISP choices and 1 is poor at best. So I quit messing around and I only use private proxies, and frankly these days I do 99.9% of everything from my dedi servers anyway. Hosting companies are a dime a dozen and you can side step to the next if need be. None the less I still use proxies with them, as I don't want to deal with it, I just had been testing without proxies for forum profiles, and well, thats what happens.
A VPN is a great choice, at that you might not even need proxies, if you get a tollerant VPN provider.