Pleasanton Community Service Officer Shannon Revel-Whitaker told a group at the Senior Center this week to be wary of anyone calling and asking for money or personal information of any kind.
Revel-Whitaker said one con, known as the grandparents' scam, has been used locally for about a year.
A caller claims he or she is the victim's grandchild in a foreign country and generally weaves a tale of being in an auto accident or another problem. The "grandchild" says that she or he needs money to get out of the trouble and pleads with the victim not to tell the parents.
The victim is asked to wire money, which can be picked up at any Western Union or similar agent in the world.
"They're very good at persuading you to do things, so don't ever, ever wire away money," Revel-Whitaker said. "Especially Western Union -- once it's gone, it's gone."
Another lesser-known scam is centered around computers. A caller claims to be from the victim's Internet service provider or from Microsoft, telling the victim that there's a security problem or bug that needs to be fixed.
Revel-Whitaker said the scammer asks for the victim's IP (Internet Protocol) address.
"Once you've handed over the address, they can get access to your computer," she said. "No reputable company will ever call you and ask for information."
If in doubt, Revel-Whitaker told the group, get a number for the company from another source and verify that it is initiating the call.
That should be standard procedure for any request for information, she added, whether by call or email -- check with the company purportedly asking for information by getting a number or email address from an outside source.
The third swindle detailed by Revel-Whitaker is known as the IRS scam. A caller claims to be from the IRS and says the victim owes money.
"You owe us some tax money and if you don't pay us that money, we're going to come and arrest you," is the line used by con men to snare their victims, Revel-Whitaker said.
She said the victim is asked to buy a prepaid debit card to get money to the agency immediately.
Revel-Whitaker said the scammers usually suggest a debit card from Walgreens (known as a green dot card). As is the case with wiring money, the victim provides a code that the con artist can redeem anywhere.
She said that scam usually targets people from countries where the police are feared.
In one recent case, she said, the scam was stopped by a clerk at Walgreens who told the victim the IRS would never operate like that.
Revel-Whitaker also pointed out that telephone scams are difficult to investigate. She said the callers may show a local number but be based in another state or show a U.S. number but be operating outside the country.
"It's simply so cost intensive that we can't investigate it," she said.
Questions from those in attendance included what to do about door-to-door solicitors.
Revel-Whitaker advised people to respond without opening the door. That would let a would-be burglar posing as a salesperson know someone is home, and would also discourage an overly enthusiastic vendor who might literally put his or her foot in the door.