Take a second look at that signed Picasso print you bought on eBay.

A ring of art counterfeiters has sold thousands of prints since 1999 bearing the forged signatures of Picasso, Miro, Dali and other famous artists to buyers around the world.

"Thousands of people will learn they ... bought a fake," said Chicago-based U.S. Attorney Patrick Fitzgerald, who announced indictments on Wednesday charging two Americans, a Spaniard from Barcelona, and two Italians from Milan and Monsummano with multiple counts of fraud.

U.S. authorities will seek to extradite the Europeans.

Sale prices ranged up to $50,000 for counterfeit prints that came with forged artists' signatures and fake certificates of authenticity that were sold in galleries, at art shows and through Internet auction site eBay, Fitzgerald said.

The counterfeits were produced in Spain and Italy, with the volume of fakes such that two of the alleged conspirators warned another one not to flood the market.

While buyers are stuck with the bogus works, prosecutors offered a Web site where they can provide details of how they were scammed: www.usdoj.gov/usao/iln.

Andrew Stern, Michael Conlon and Todd Eastham