Sanctity of Communication
This is a concept that, despite the chorological nature of its creation, comes before the actual advent of spam and telemarketing. The basic principle is that there is a sanctity in individual communication, and that there are certain actions that can violate this sanctity, such as using that form of communication for other then its intended purpose.
Illustration by example ? You and a good friend are sitting on a park bench having a smoke / coffee / breath of fresh air and discussion life, in whatever form that you feel like talking about it. All the sudden a seedy looking fellow/lady walks right up to you and tries to sell you Rolexes / marijuana / Asian hookers. The action of this fellow / lady violated the purpose of the from of communication that was being used, chatting in this case, and usurped it for their own goals, again, in this case selling.
We already see the affects of this idea in our society. You cannot use your CB radio in police channels. They get upset. There are laws governing telemarketing and getting on privacy lists. MSN 8's biggest selling platform was that it claimed to stop junk mail. Money talks in government, but these are things that annoy EVERYBODY. Even those who own spam email operations, so it is a matter of time before we see a Sanctity of Communications Act, which will outlaw once and for all that pesky telemarketing and spam.