Javascripts that kill popups on free hosts are illegal, right? This Please do not link to this type of site has a bunch. Would that not be agreeing to most site's terms of service?

Yes, it's illegal.

Part of the agreement you make when you sign up is that you get free space, and they advertise on your site to make money.
It's the price you pay I guess.

Try getting hosted by an independantly owned domain if the ads bother you.

not only are those scripts against hosts' terms of service, posting them or linking to sites with them is against this forum's rules.