A rule prohibiting mobile-phone spam adopted by the FCC earlier this month doesn't prohibit phone-to-phone text messaging, but FCC officials believe the new rule, combined with a 13-year-old law, should protect U.S. mobile phone customers against unsolicited commercial e-mail.A\u00a0rule prohibiting mobile-phone spam\u00a0adopted by the Federal Communications Commission\u00a0earlier this month doesn't prohibit phone-to-phone text messaging, but FCC officials believe the new rule, combined with a 13-year-old law, should protect U.S. mobile phone customers against unsolicited commercial e-mail.The text of the new FCC order, released Thursday, notes that the FCC's Aug. 4 action to prohibit mobile-phone spam applies specifically to Internet-to-phone messages addressed to a domain name, not to phone-to-phone messages using the popular Short Message Service (SMS). The Controlling the Assault of Non-Solicited Pornography and Marketing (CAN-SPAM) Act, which\u00a0President George Bush signed into law in December 2003, authorized the FCC to specifically address mobile-phone spam sent to e-mail-style domain-name addresses.While the new FCC order covers any Internet-to-phone messages using SMS sent to a domain name address, most SMS messages use the recipient's phone number to deliver the message. The new FCC order prohibits the sending of commercial messages to mobile-phone domains without the permission of the subscriber.At least one critic questions whether the FCC's failure to address many SMS messages in its latest order could open mobile-phone users up to spam or cause confusion about what text advertisements are legal. But FCC officials say the 1991 Telephone Consumer Protection Act (TCPA) already bans most mobile-phone spam not addressed by the recent order.The TCPA restricts the use of telephones and fax machines to deliver unsolicited advertisements, and in 2003, the FCC and the U.S. Federal Trade Commission established a national do-not-call registry with authorization from the TCPA. In the June 2003 FCC order authorizing the do-not-call list, the FCC also spelled out rules that should cover most forms of mobile-phone spam not addressed in the CAN-SPAM order, said Ruth Yodaiken, an attorney advisor at the FCC.The FCC's TCPA rules prohibit marketers from using automatic telephone dialing systems to make calls to wireless phone numbers, and the rule applies to text messages as well as voice calls, Yodaiken said. With a rule against sending messages in bulk to mobile phones, most of the incentive for spammers to target mobile phones is gone, she added.And while the prohibition against auto-dialers doesn't address SMS-based advertising sent from one mobile phone to another -- a tactic too expensive for many spammers -- the national do-not-call list should cover that form of unsolicited advertising, Yodaiken said. The list protects people who sign up for it from unsolicited phone-based advertising, and the FCC rules include text-based phone advertising on the list of prohibited activities under the do-not-call list, Yodaiken said.The rules adopted by the FCC this month should close a hole in the protections against mobile-phone spam not addressed in the TCPA - spam sent to mobile phones through e-mail-style addresses, Yodaiken added. "We're trying to close the net there," Yodaiken said. "We're hoping we get most of it."But Royal Farros, CEO\u00a0of MessageCast, suggested the two sets of rules may cause confusion about what types of mobile-phone spam are prohibited. "Why are they chopping it up into certain devices and certain domains?" he said. "It seems kind of piecemeal to me."Although the amount of SMS spam is low in the U.S. compared to Japan and some countries in Europe, Farros questioned if the TCPA rules protect U.S. mobile phone users against spam. One in every two mobile phone users received a piece of spam in 2003, estimates analyst Michael Sampson of Ferris Research. Ferris Research expects the amount of mobile-phone spam in the U.S. to rise to one message per every mobile phone user in 2004, and three pieces of spam per mobile phone user in 2005, Sampson said.There are currently 167.6 million mobile phone service subscribers in the U.S., according to Cellular Telecommunications & Internet Association (CTIA). In December 2003, 21 billion text messages were sent to mobile phones in the U.S., although many of those messages were not commercial spam, according to CTIA."If they're telling us the protections are clearly in place, then where are the protections?" said Farros, whose company sells software that allows commercial messages to be sent to mobile phones and other devices, if the customer opts in to receive messages. "If (mobile-phone spam) is already covered, then it's not working."But CTIA disagrees, with spokeswoman Erin McGee saying the association believes enough spam safeguards are in place for mobile-phone users. Mobile-phone carriers have sued spammers and taken other measures, such as installing spam-blocking software on their networks."With CAN-SPAM, along with the TCPA, along with what wireless carriers are already doing, there's a good level of protection for customers," McGee said.