C&D] They can, but will they?

*. They have to know you're there.
2. They have to speak your language or the language of the sites you visit.
*) They have to care enough to go to the trouble
4) This is very difficult for them if you have a dynamic IP (every time you log on you're a 'different' person as far as they know.
5) You'd have to move a lot of data to even come to their attention.

E] Those neatly provided for you on websites, absolutely.

Of course these are just one dude's wild-eyed, uninformed opinions :-)