I just don't understand how it is society allows invasions of privacy such as telemarketing.  It must be a matter of commercial interests being put above the interests of the public.  I have a similar view of billboards -- no matter where they are they are an unavoidable and ugly intrusion, and sometimes they are outrageous in spoiling the view.  If we had choice in whether to see them or not it would be acceptable (such as a mute on the TV) but when they impose themselves they should not be allowed.