About Phone Fraud
Phone fraud: someone calls you with an offer "too good to be true", or tells you that there's a problem with some account of yours (or with your computer).
Sometimes things are simpler than you think. They may just want you to call back.
If you get a text message (or see no message on your answering machine, just a phone number), or if someone asks you to call them back about winning a lottery or free vacation, it's because they want you to call back so they can to talk you into something. Don't. Just calling can cost you money. Never call back a strange long-distance number. Don't ever dial area codes 900, 876, 809, 649, or 284. Those calls will cost you $25/minute or more... but you won't know that until you receive your phone bill.
Sometimes (usually when it's a recorded message), they may ask you to hit a key on your phone. Don't. It may have side effects you don't know about. If someone calls you with a pre-recorded message, simply hang up.
If it's a real person telling you that you've "won" something or offering something for free (or "too good to be true"), just decline and hang up.
If someone claims to be from your bank or other business and starts to tell you that there's a problem with your account, tell them you'll call back. Don't trust any number they give you: look up the number and call the the bank or business directly.
If someone calls "from Microsoft" or "Windows Support" saying they're calling about a problem detected on your computer, hang up! These calls are always fraudulent (no matter what the caller says). Microsoft does not -- and prohibits their contractors from -- making any such calls. In addition to trying to get personal information and/or a credit card number (to pay for "fixing" your computer), they may also try and trick you into installing a program on your computer, so they can control it. A call from your Internet service provider could be bona fide; but don't take their word for it, call your ISP back directly.
To opt out of receiving telemarketing calls, register all your phone numbers with the National Do Not Call Registry by calling 888-382-1222 from your phone. Or, online at https://www.donotcall.gov/register/reg.aspx. (Registration lasts indefinitely; you do not have to renew.)
After about a month, you should no longer get bona fide telemarketing calls. So... if you get a telemarketing call, you'll know right away that it's a probably a fraud. [Businesses you already do business with, political organizations, surveyors, and charities can, however, still legally call you.]
Just hang up when you get a telemarketing/fraudulent phone call. Especially if it's a robocall (a recorded message); don't click on a key. Do not call them back.
If you call back to a "toll-free" number, you shouldn't be charged for the call. But no matter what someone might tell you: 800, 866, 877, and 888 are the only "toll-free" area codes.
Whatever else you do, never, ever give out personal information or your credit card number to anyone who calls you. You should be the one who calls them (after first looking up the number of the business or bank you want to talk to, to ensure who you're talking to actually represents the business).