Legal Question in Civil Litigation in California

It's called a shredder. You can get one at Office Depot.

If you put your trash in a dumpster that you were not supposed to use, then it would be reasonable for the owner to go through the trash enough to verify who had used it without permission, but it would be an invasion of privacy to use the contents to contact any of your clients. If the person he called thought the call was indicating you had done something illegal, then there might be a cause of action for defamation, but how much in damages could you show? Likewise, you have grounds to sue for breach of contract and his attempt to illegally lock you out [taping the door shut], and might be able to collect for the increase in rent you have to pay in a new location and the cost of the move and interruption to your business. Your major problem is showing you have enough damages to justify the cost and trouble of a lawsuit and finding an attorney who would handle it, unless you are satisfied with the $7,500 limit of Small Claims Court, where often not much may be given for pain and suffering damages.