(MONEY Magazine) – Telephone con artists are moving into the charity-scam business in a big way. "Telemarketers who used to peddle nonexistent oil leases or 'rare' coins are turning to fake charity solicitations and pocketing the donations," says Eileen Harrington, the Federal Trade Commission's top telemarketing cop. Here are five tip-offs to trouble. The unknown fund raiser who phones: -- Won't send written material on the charity. -- Says you've won a prize -- if you make a donation. -- Presses for your credit-card number. A legitimate group will happily accept your mailed check. -- Claims to be aiding victims of a recent tragedy -- a blizzard, say. Call your local newspaper to check who is actually collecting donations. If you do get burned, holler -- to the police, or your local Better Business Bureau or consumer affairs agency. But Harrington urges generosity. Not giving, she says,"would be the con artists' ultimate victory."