not quite true, the tippmann flatine barrel on a tippmann can be classed as a sniper marker if you are playing rec ball in a big area. I can pick people off at between 250 - 300 feet and they aint got a clue where the shot is coming from. Obviously the setup has to be perfect, also what type of paint you use effects how well you shoot.
If you willing to get into position and have a clear view to the maximum range and you are a good shot, I would say you could hit 9 our of 10 of your victims. The key to sniping is not rapid fire but just fire 1 or 2 shots at a time, if you are well hidden they will not be able to identify where you are, they will stand, crouch or lay down looking around and then you fire and they are hit and out.
You need a lot of patience, its a lot harder to play this sort of game in the UK because the game play does not really allow you to do this sort thing unless its a big scenerio game, but in the USA well thats another story!!!
This is only my opinion