In command blocks, arguments such as coordinates and radius seem not to work!
Ex:

tp @a[x=0,y=100,z=0,r=0] ~0 ~0 ~5

Normally this would only teleport players in the radius of 0 at 0,100,0 5 blocks away, but instead teleports everyone in the server 5 blocks away

This only happends when r=0 or their is no r=.