What's much more likely is someone intercepting your messages at YOUR end. There were an awful lot of computers out there with the Subseven trojan in them before I completely shut it down in my firewall. It was just getting WAAAAY too bothersome to deal with the attacks individually and pretty well all of them come from infected machines. If someone can plant the trojan in your system and you don't know it's there, it can turn over a copy of everything you type or file. Nailing a web server is also possible, but those tend to get their holes plugged much more promptly...