I think an excellent feature of mirc should be to allow people to change their /whois information at will, to circumvent frivolous bans.
Excuse me while I go laugh my ass off.
Newsflash - you do not have a god-given right to access any network or channel on IRC. If somebody wants to ban your whole ISP from a network or channel, it's their right. Privately owned networks; privately run channels. If you're banned, tough luck - either contact the channel / network owner or operators, or find another channel / network to chat in.
Think of a house. The house owner decides to not allow anybody with green eyes inside his house. Even if it's "not fair", it's his right to do that, and I doubt you'd be clamoring for somebody to hand you a pair of eye-color-changing contacts just to get inside that house. You'd find another house to visit.
You said it yourself "any other convicted thief".
Well, I got banned without being convicted of anything. I did nothing, and am still banned.
No, he said "any other convicted thief, or person I deem a thief" (emphasis mine). In this case, you're being deemed a thief. Tough luck, find another place to chat.
