Telemarketing firms should not be allowed to leave callless voicemails.  The rules that apply to regular calls (which are pretty toothless) should apply here as well.  If telemarketing firms are allowed to do this then we'll have the voice mail equivalent of the spam epidemic that we experience with email to this day.

The notion that banning ringless voice mails is a violation of the first amendment guarantee of free speech is ridiculous.  If that were true, then the Do Not Call list is a violation of the first amendment as well.  People and companies have a right to say what they want to say (wihtin reason), they DO NOT have a right to force me to have to listen to what they want to say, not even for a single moment.