First I have to say that I work for the company that I'm talking about. Ok, now that's out of the way. Primus Canada recently launched a new service where we give the customer the ability to control telemarketing calls. Think of it like spam filtering but on telemarketing calls. This has reduced inbound Telemarketing VERY substantially for our customer base. Do not call lists are all fine and dandy but they aren't that reliable. You can learn about the feature here:

http://www.primustel.ca/en/residential/guide/tmg/TelemarketingGuide.html

The best call treatment is the "press 1 jail." If the number is identified as a telemarketer the telemarketer needs to "press 1" in order to reach the customer, since 99% of Telemarketers can't send any digits this effectively blackholes them. Works a charm.

Paul