Thousands of dock workers attacked the European Parliament building this week, smashing windows and fences in a protest against a bill that would allow competition in cargo handling. Some 6,000 rioters inflicted several hundred thousand dollars worth of damage to the building before riot police dispersed them with water cannons. Cargo at E.U. ports is currently handled by local monopolies. Under a proposed reform, companies would be required to bid for cargo handling contracts, and workers fear their wages would be cut as competing companies are pressured to lower their prices. Analysts said the dock workers need not worry. The E.U. executive body has pushed for competition in a number of sectors, and the European Parliament always rejects it.