Text message on my cell announcing car dealer going out of business. It said go to www.greatcarsusa.com and to enter a code. No thanks, might be infected. I called the number that sent the text (from an unused phoneline at work) and got a recording saying the voice mailbox for that user hasn't been set up yet.
I called 611 from my Verizon cell phone and the rep. I spoke with put a block on future text messages from this number (408-406-5944). Other providers might do the same. You can also manually block numbers at www.verizonwireless.com. Log in (register if it's the first time), go to My Services, then Spam Control and enter the number.
It's got a 5 number limit, and it expires, but it's better than nothing. And you can re-add the number, if necessary. Too bad Verizon home phone service doesn't have this free feature.
There's also an option to block text messages from domains.