As mentioned in the Toronto Star:

Of course, it won’t work since there are exceptions for “charities, political parties, pollsters and established business relationships.”  The latter is the biggest problem… do you think it’s restricted to direct business relationships?  Will it also allow “business partners” to call you repeatedly with automated dialers 50 times a day and when you finally pick up they don’t have an agent available for more than 10 seconds?  Will it allow the business parter of those business partners to call you?  When they break the rules, will there be consequences or will you have to go to trial to stop an offending telemarketer from calling you?

In any case, a telemarketer can just open a limited lilability corporation that breaks the rules; when the hammer is about to drop, they can close shop and create a new corporation.  And what about foreign companies using VOIP to call you for real cheap?