incrediBILL - 6:53 am on Dec 11, 2012 (gmt 0)
There are apps for that.
You can whitelist your contact list and totally eliminate any spam whatsoever, whether it's text messages or email.
I also had to also block nuisance telemarketers from calling my cell phone.
Since the phone companies charge for these services. unless you have unlimited plans, they have no real motivation to help block them because it runs up revenues and if you have an unlimited plan they can just brush it off as it costs you nothing extra to be annoyed.
Recently overheard when wife put spammer on speaker phone and asked him to prove he was from Microsoft Security, in a thick Indian accent, "Go away lady!"