Two researchers at Georgia Tech can tell you exactly how American ISPs shape Internet traffic, and which ones do so. Bottom line: of the five largest Internet providers in the country, the three cable companies (Comcast, Time Warner, Cox) employ shaping while the telephone companies (AT&T, Verizon) do not—though that fact is less significant for the user experience than it might first sound. (http://arstechnica.com/tech-policy/news/2011/05/new-shaperprobe-tool-detects-isp-traffic-shaping.ars)

Virtually all the major Canadian ISP's have admitted to throttling traffic.

I ran the tool on my computer. I have MTS Lightning Bolt, and it seems they aren't throttling. It was ran just before this post, so I don't know if they are throttling at other times. Here's the output below:
DiffProbe beta release. October 2009.
Shaper Detection Module.

Connected to server 64.9.225.166.

Estimating capacity:
Upstream: 1928 Kbps.
Downstream: 30485 Kbps.

The measurement will last for about 2.5 minutes. Please wait.

Checking for traffic shapers:

Upstream: No shaper detected.
Median received rate: 1904 Kbps.

Downstream: No shaper detected.
Median received rate: 29866 Kbps.

For more information, visit: http://www.cc.gatech.edu/~partha/diffprobe

In Canada, the CRTC requires that ISPs must inform consumers of their traffic shaping practices.

I happened to be looking on the MTS site last week and couldn't find anything about throttling in their internet policies, so that confirms they don't do it.

i really dislike MTS customer service and the once a month call that has to be made to get my bill corrected but sadly if my data cap becomes an issue I might be going back to mts.