re: Hasn't this been discussed before?

I don't know why people keep thinking they have nothing on their PCs worth having so no one would want to break in. It's not about the PCs on the network. It's about the outgoing internet connection.

Wireless hot spots and corporate lans are usually strictly filtered so not as useful as a home network which usually isn't. Given access to your network they can now do things that they wouldn't want traced back to themselves.

The list includes:

Spamming

Attempting to break into other computers

Viewing child porn. (they actually caught a guy doing this in Toronto)

Any one of these will leave you in a "guilty until proven innocent" scenario as far as your ISP is concerned and may result in legal trouble as well.