Thousands of small-business owners may be accruing hundreds of dollars in charges for Internet services they never signed up for. The scam is called "cramming." It usually starts when someone calls a business to confirm telephone and address information, then mentions briefly a "free" service. The unsuspecting company is then enrolled in the service, and a fee is assessed through its phone bill.

It took Joe Breese, owner of a wedding photography business in Mount Vernon, N.Y., three months to discover an unwanted $50 charge. "When I called," says Breese, "they said, 'There's nothing we can do for you." That's common. Crammers often make seeking a refund such a hassle that their victims give up.

So far, the biggest cramming bust involved Epixtar Corp., a public company based in Miami doing business as Liberty Online Services, National Online Services, and SBA Online. Epixtar, which declined Inc.'s request for an interview, reached an agreement with the government in November to revise its business practices.