Among the biggies is the "tech support" ruse. That's when con artists, claiming to be tech support worker, call and tell people a virus has infected their computer. And they offer to fix it for a price. Then they take over the computer by remote access.
It happened to Fern Johnson of Novato. She said someone called her saying, "'I'm calling from Microsoft to inform you that your computer is loaded with virus and will crash.'"
"If they're on your computer, it's game over. They can do anything they want. They can install malware to add you to a part of a remotely controlled network," said Harrison.
Other common types of fraud are smartphone snatching. That's when someone asks to borrow your phone, then takes off with it.
There's also gift card fraud where con artists claim you've won a gift card, but must pick it up in person. When you leave, they break into your house.
And with online purchases, one popular scam is a buyer sends a check for more than the purchase price. The seller wires back the difference, but finds out later the buyer's check was a fake.