If you create a "beaming"-area in multiplayer mode, for example with "/tp @p[x=-1,y=0,z=-1,dx=2,dy=100,dz=2] 2 64 0", all the players on the server are teleported to (5|64|0), not only those near the point of origin. There is no problem in singleplayer mode. It not depends on the tp-command.
Could duplicate: MC-62180