Recently pried off a trailer of a British man, the work of famous street artist Bansky, called “Silent Majority,” which depicts a commando raid to install sound gear for a rave, goes up for auction Monday in Paris. The Digard auction house hopes it will fetch at least $400,000. Failing that, the plan is to put it up for private sale. In 1998, the truck owner knew Banksy as someone he had once busked with in Bristol, England, and the friend of his sister’s boyfriend, and for 200 pounds (about $300 at the time), he agreed to turn his trailer into a blank canvas for the Glastonbury music festival.