Never experienced it, but that's probably because I've got adblocker plus installed:
Best thing that's ver been installed on my computer.
Good idea - assume you're sure its not spyware in disguise?!!
Nah, recommended by some extremely fine upstanding publications, as well as some real techies. Most people I know now use it. It's amazing how quicker it makes things as well. It does stop lots of ad cookies and other dubious scripts hidden in adverts downloading too.