Ok heres the deal with it...
Right now major internet providers have caps in place already. All of them do. Its not one set cap, it depends on the service you pay for.
For example Shaw's download cap is broken down kind of like this..
Shaw high speed lite -15gig
Shaw high speed -60 gig
Shaw high speed extreme -100 gig
Shaw high speed warp -175 gig
Shaw high speed nitro -350 gig
Its already in there Acceptable use policy.
(
http://www.shaw.ca/en-ca/AboutShaw/TermsofUse/AcceptableUsePolicyInternet.htm)
So these caps are already there. If you go over your cap once usually you will hear nothing or a letter at most, you go over twice or continue to go over then they may charge you for each gig you go over.
That is already there and is not being debated unfortunately.
What is being debated is the CRTC stated that the small internet providers would not be able to sell unlimited internet and would have to have caps as well which the big internet providers want so the small guy doesn't have an advantage and the small provider is using the big providers infrastructure. The small internet providers state that if they have to cap as well it will ruin there business and also greatly affect innovation in the internet field. Part of the argument they have is a business like Youtube or Facebook would never again be able to happen due to costs unless you were of course a big business already.
The Feds have said (unofficially) that if the CRTC doesn't change there ruling then they will step in and stop it from coming in affect so they can still sell unlimited internet. Not just the small guys but that any company can sell unlimited internet (just the big guys don't want too)
Another big worry people have is if this goes through and theres no more unlimited internet then internet plans will end up being a lot more like phone plans , instead of minutes you pay for gigs etc.
Open media has a lot of information on it, Hope I didn't ramble on to much
http://openmedia.ca/