Listen up, telemarketers, Nigerian princes and far-flung pharmacies trying to get me to buy Viagra: You may annoy me via email, postal mail and even via Facebook, but when you start harassing me via text message, you’ve gone too far.

And yet, somehow, they don’t seem to care. According to The San Francisco Chronicle, spam SMS in the U.S. surged 45 percent in 2011, to 4.5 billion. The costs associated with this are huge. For many recipients, it’s galling to be targeted by these messages, but it’s a whole new level of irritation to have to pay for it. Then there are the carriers, who field customer-service calls from irate subscribers at $5 to 50 a pop.

The Federal Trade Commission filed suit against some of the major spammers last year, but that hardly seems to have made a dent. Perpetrators are loving this brave new world of cell phone spam texts, since it carries none of the peskiness of email junk mail filters. And since it’s easy to find phone numbers online or crunch out random phone numbers every moment of the day, there’s not much to dissuade them. In one case, the FTC even charged a spammer of sending 5 million junk messages (mostly about loan-modification programs and debt relief). According to the agency, the accused sent out as many as 85 spam texts per minute, 24 hours a day.

There’s no doubt about it, the mobile spam scene is exploding. And we all need to brace ourselves, because it’s only going to get worse from here.

Do you get spam texts on your phone, or do you have a strategy that helps you avoid it? Let us know in the comments.

[via The San Francisco Chronicle]