Last year, messaging security firm Cloudmark conducted a survey and found that 66% of Britons had received spam on their phone via SMS or MMS. That number is surely going to increase.The survey had some other interesting statistics as well. Some 28% of victims blamed their carrier for the spam and 44% would consider switching carriers, and that number rose to 65% if they started receiving more than one spam message a month. I am not sure the carrier can be blamed directly for the spam, but they can be held accountable for not doing enough to block the messages from getting on their network and to their customers' phones. I've only received a few spams on my phone, but they can be quite irritating. I am not a heavy SMS user. I frequently text family members or update my Twitter status, and that is about it, so when an SMS comes in, I naturally assume it is from my family so I look at my phone pretty quickly to see what the message is about. Seeing that it is spam is frustrating, as is knowing that as the end user, there is nothing you can do about it -- you don't even have the satisfaction of marking it as a "Junk Message," even though we all know that really does little good on your desktop either. A lot of people have unlimited messaging plans, but not everyone does, so unlike spam on your desktop, a spam message on your phone can cost you money. If you are traveling and roaming on another network, especially in a foreign country, the messages become costly very fast. I am sure many carriers have some measures they take to prevent spam, but it obviously isn't enough. I can think of two measures that would significantly reduce spam if the carriers would implement it. First, they could block all messages that aren't in your contact list. That seems pretty straightforward and, unlike e-mail filters, this generally makes sense. Think of how many SMS messages you send to people that aren't in your phone's contact list. I suspect it isn't many. The second measure would be to whitelist anyone you send a message to. That would cover the occasional texts to people you haven't bothered adding to your contacts. There are obviously costs associated with this, as well as logistical issues, like how do you get the contact list off the user's phone onto the carrier's system to begin filtering, and more important, how do you keep that contact list secure? Right now, mobile spam isn't anywhere near the volume it is on your computer, but if it approaches even 10% to 15% of the volume spam you get in your e-mail account, it would render messaging on the phone next to useless. The carriers need to be very proactive in this area, touting their spam-protection features as part of their marketing. It will keep existing customers happy and potentially win customers from less-aggressive carriers.