(FORTUNE Magazine) – Nobody knows if Congress's multi-tentacled bill will actually curb illegal immigration, but it will surely confuse and complicate hiring for U.S. companies. Says labor lobbyist Virginia Lamp of the U.S. Chamber of Commerce: ''We're going to have a lot of litigation and a lot of new bureaucracy and paperwork as a result of this legislation.'' All U.S. companies, from Anchorage to Miami, will have to check and keep on file documents that demonstrate every new employee's legal right to work in the U.S. Stiff penalties may result for companies that fail to do so. Some executives polled by FORTUNE in a random survey shrugged and said they could handle the proposed law and its hassles. The businesses hurt most will be those that depend on illegals for cheap labor -- mostly small ones such as restaurants, garment sweatshops, and landscaping firms. But big companies will find that compliance won't always be painless. An executive at San Antonio-based Datapoint questions whether, in looking at documents such as birth certificates to check legal work status, companies might become vulnerable to charges of age discrimination. And the bill sets up an entirely new Justice Department office to protect the civil rights of aliens that in some ways duplicates, and may conflict with, the Equal Employment Opportunity Commission. ''Frankly, the business community won't understand the law or how to comply with it,'' says Representative F. James Sensenbrenner (R-Wisconsin), who predicts its costs to business will be staggering.

Whatever the bill's other effects, it will certainly help at least one industry grow: the already booming one that specializes in forging identification documents.