Given the sheer number of ads, video overlays and extensions that most users have to contend with - even on mainstream sites (I'm looking at you cnn.com) - I'd

Given the sheer number of ads, video overlays and extensions that most users have to contend with - even on mainstream sites (I'm looking at you cnn.com) - I'd bet that a large percentage of users would just think that their browser was acting strange and proceed as normal.