Caller ID "spoofing," is another technique used to make it appear as though the call is coming from a legitimate business. However, the company name and number that comes up on your phone is really a fake one. There are even legal commercial services that allow callers to choose their area code and prefix, so they fool you into thinking they are calling from one location, when in reality they are calling from another.
SMS phishing is also like Internet phishing on your cell phone. Some fraudster is trying to steal your personal information by tricking you with a text message or email that directs you to go to a fake Web site (that appears legitimate) and enter personal information, like your bank account login and password. SMS spamming is unwanted junk mail delivered as text messages to your cell phone. If spam is a problem for you, check with your cell phone company as they might have spam blocking available.
The SIM card inside GSM phones securely stores not only the contacts in your phone book, but also other personal information to prevent the fraudulent use of your service. It also secures your calls with encryption so they cannot be eavesdropped.