It all depends on your chip-stack and if you can afford to lose a few chips? If I am on the button and the BB and SB are sat out, sure I will steal with any two cards, and even if I find a player with fewer chips than me sat behind a sitter I will raise in any position to try and steal the blinds, sometimes especially when close to the bubble even a 2 X raise is enough to get the job done.
Stealing blinds from sitter's is not a crime, and what really annoys me most is when there is a sitter on the BB and the small blind folds to the sitter keeping him in the game. I see it all too often when you get a novice playing.
There might be a perfectly reasonable explanation for people sitting out in a Tourney, (lost connection, or called away on other business), but to fold to a sitting player is a useless waste of everyone's time.
When the fun Stops, STOP!