It seems that Qwest can"t decide if it"s throttling bandwidth or not. A user on Consumerist.com states that Qwest tech support told him that they do throttle their bandwidth for excessive users, and then sometime later, the tech support agent called him back and reported that they do not throttle bandwidth.
According to the user who is based in Washington, Qwest puts rate limits on streaming intensive sites like Youtube. The user confirmed this by running several speed tests and then viewing Youtube again and was receiving the slower data rate. Then by using an external proxy he was able to achieve much faster speeds than if he directly connected to the site.
After several escalations of different help departments the user was cited to the TOS where it discussed rate limiting for heavy users. After ending the call the Qwest user received a call back from the tech agent who then stated that the company does not throttle bandwidth.
While we may never know the truth about ISP"s and bandwidth throttling one thing for sure is that the practice is becoming more wide spread. Time Warner and Comcast are already testing the waters and it won"t be long before it"s rolled out nationwide.