Cyber-crooks are spamming through every avenue they can, hoping to lure their victims into revealing personal information or tricking them with scam SMS text messages. A technique, also known as smishing (SMS phishing), that is rather effective because it reaches your own personal phone. The cost of a single message can be something like $10. Repeat the screen a few times and thats enough to rack up a huge bill. As a rule of thumb, you should only ever text people you know to avoid nasty surprises.”]
Source: https://blog.malwarebytes.com/cybercrime/2013/07/sms-scams-how-to-defend-yourself/