Well,, I can't imagine one of top players durning their off days at home or wherever, randomly surfing the net, and not thinking about looking up to see what is being said about them. It's human nature to want to know. Plus, you just type in "tennis forum" or anything like that in google and this site is the first one that tops up.
Just cause they're famous(relatively) don't mean they dont do normal things like the rest of us
Plus, I'm sure they're PR
people (for those that have them and acutally seem to care) check up pretty often.