Does Blockbuster Edit Their Movies?

I have heard reports that Blockbuster edits [censors] some of their movies. Some really "spicy" R-rated movies supposedly have some scenes cut to tone them down. Also, I was told that in their version of the movie, TITANIC, the scene in which Leonardo DiCaprio sketches Kate Winslet has the nudity cut out, and this movie just has a PG-13 rating. Obviously, any alteration in a movie's rental release would have to be approved by the film's distributor.

So, fact, or urban myth? I am just starting to rent movies again, and I need to know for sure. And please, let's not get into a Blockbuster bashing!