There is yet another scam that criminals are using to invade people's online security, and it involves getting people to click on a link to a bogus website on their cell phones. After the link is clicked, a virus of some kind is downloaded to the phone. This act is called Smishing. It's a combination of SMS + phishing; it is activated when a text message is answered.
The text message usually alerts the intended victim that he or she needs to take "immediate action" or give an "immediate response" to the message. Then, as soon as they fall into that trap, their private information has been put in jeopardy. So, it's best not to respond to random text messages from strangers--no matter how "urgent" they try to make you think your response is.