NEW YORK - Text message spam has started waking Bob Dunnell in the middle of the night, promising cheap mortgages, credit cards, and drugs. Some messages offer gift cards to, say, Walmart, if he clicks on a website and enters his Social Security number.
Once the scourge of e-mail providers and the Postal Service, spammers have infiltrated the last refuge of spam-free communication: cellphones.
In the United States, consumers received roughly 4.5 billion spam texts last year, more than double the 2.2 billion received in 2009, according to Ferris Research, a market research firm that tracks spam.
Spread over 250 million text-message-enabled phones, the problem is not as commonplace as e-mail spam. But it is a growing problem, with the potential for significant damage.
“Unsolicited text messaging is a pervasive problem,’’ said Christine Todaro, a lawyer with the Federal Trade Commission, the consumer watchdog agency, which is turning to the courts for help. “It is becoming very difficult to track down who is sending the spam. We encourage consumers to file complaints, which helps us track down the spammers, but even then it is a little bit like peeling back an onion.’’
Although some text spam is of the harmless, if annoying, marketing variety, a vast majority is more insidious, experts say. With one mobile tap, smartphone users risk signing up for a bogus, impossible-to-cancel service.
Or they may succumb to that offer for a Walmart gift card or a free iPhone in exchange for taking a survey and divulging personal information, like their addresses or their transaction history - which can then be sold to digital marketers or even used to crack their bank accounts.
And it is hard to stop it. Even replying to unwanted messages with “NO’’ or “STOP’’ - the usual method for unsubscribing from an unwanted text message list - may only verify to spammers that you have a working number that can then be resold.
Scrambling to get a better grasp on the problem, the mobile industry last month joined with a maker of antispam software, Cloudmark, on a new reporting service that lets users forward mobile spam to “7726,’’ a number that spells SPAM on most keypads.
Carriers will then use that information to block numbers.
Mobile spam is illegal under two federal laws - the 2003 Can Spam Act and the Telephone Consumer Protection Act, which set up the Do Not Call Registry in 2003. Smartphone users can report numbers that spam comes from on the websites of the FTC and the Federal Communications Commission.
The major wireless carriers - AT&T, Sprint, T-Mobile, Bell Mobility, and Verizon Wireless - all also offer ways to report the numbers on their websites and can block numbers. A number of apps for Android phones also promise enhanced spam text filtering.
Spammers, though, are endlessly inventive. Mobile carriers and filtering software can detect when a large volume of spam is sent from one phone number, and when the texts try to get someone to click on a website.
So spammers are turning to large banks of phone numbers, regularly changing the websites they try to get consumers to click, and blasting their messages from the Internet using “over the top messaging systems,’’ which let them send millions of messages cheaply.
The minute a carrier blocks one number, spammers simply start using another.
“It seems this is all coming from different sources,’’ said Dunnell, a financial security consultant in St. Louis, who reported some texts he received on the FTC’s website and signed up for the Do Not Call list - to no avail. “I don’t know what good blocking one number will do.’’
Legal remedies may provide some help against mobile spam. Verizon has brought 20 lawsuits against wireless telemarketers and spammers, most of which have been settled.