Other than making them stoned, it will have no significant effect at all.
They will actually start wanting to improve either the amount of the cannabis they're taking or most likely moving on to a better drug, like crack meth or something else.
You get irritated that you don't smoke weed on a daily basis!
don't smoke weed
Nothing
They can get simulated.
Your penis dies
you get phucked up
You get happy and hungry and sleepy
Nothing
Yes, I have seen many people buy it on a daily basis who I know smoke weed.
Nothing that wouldn't normally happen when you smoke.
You trip major balls brochacho.
You smoke my weed!