AdBlock and NoScript (if you use Firefox). If you use Chrome I know there's an AdBlock plugin for it, but Chrome itself is rather creepy (unless you don't log into Google). Welcome to the future, where creepiness is part of everyday life (your cell phone tracks everything you do anyway). You're likely being tracked thru Google - ever notice how a Google search will put "personalized" ads on unrelated websites of things you recently searched for? Personally, I use Duck Duck Go and only sign into Google when I have to. Otherwise, I'm signed out. Even that ain't a guarantee ;).

Laurie