The FCC is busy protecting us from mobile phone spam:
But the FCC exempted from its spam definition any short message service, or SMS, messages that go directly to phone numbers, which could create a large loophole through which millions of junk messages may travel.
The agency also exempted "transactional" and "relationship" messages—such as billing statements or simple customer information. But it left the definition of what messages fall under those classifications to the Federal Trade Commission.
FCC chairman Michael Powell said he was "very proud to have just flatly prohibited spam on wireless devices"
For some definition of "spam" and "flatly".