Many of the state's senior citizens have good pensions and are conservative spenders, but are very trusting, which can put them at a disadvantage with persistent telemarketers, according to McGraw.
There are a number of bogus telemarketing pitches, including some for sweepstakes drawings, that people should be warned about, McGraw said.
Some calls encourage people to purchase merchandise such as jewelry or magazine subscriptions for a chance at winning a contest, he said.
After making the purchase, buyers may be told they must make another purchase if they want to move to the next level of the contest.
Investigators have found cases in which buyers had purchased several subscriptions to the same magazine to increase their chances of winning, officials said.
In many such contests, money is never awarded, McGraw said.
Another telemarketing ripoff involves calling people and telling them they have just won a new car, said Rhuel Craddock, an AARP official who helped organize Thursday's Operation Strike Back.
The telemarketers tell those they call that to receive the car they must send money for shipping costs, said Craddock.
"A lot of people don't want to admit they have been scammed. They even deny it to themselves," said Craddock.
Volunteers with Operation Strike Back found some savvy, and apparently experienced, telemarketing customers in the Eastern Panhandle.
Several volunteers said people hung up on them when they started their presentation. Others used caller ID to call operators back to determine if Operation Strike Back was legitimate.
Volunteer operators gave those on the other end of the line tips on how to avoid becoming victims of telemarketing fraud, such as never agreeing to send or wire money to a caller.
Operators mailed information packets to those who wanted more information.
In a typical fraudulent telemarketing operation, operators in a "boiler room" call victims using a "mooch" or "sucker" list of consumers who have been victimized in previous schemes, McGraw said.
Volunteers worked in a "reverse boiler room" Thursday, working from lists of names obtained by the attorney general's office as a result of lawsuits filed in an effort to stop telemarketing fraud in the state.
Volunteer operators hoped to contact about 4,000 people throughout the day.
A number of organizations helped in the effort, including Bell Atlantic, which donated and installed the telephones.
McGraw said his office has forced 106 fraudulent telemarketing operations out of the state through civil suits. No law enforcement agency has ever attempted to prosecute the operations, McGraw said.
Many of the telemarketing operations are located outside the state in Ohio, Texas, Florida, Louisiana, Arizona, Nevada and California, McGraw said.