FLA Chamber of Commerce suit vs. commuter self defense
Here's a pdf file of the complaint, scanned and thus rather large. The three theories are deprivation of property w/o due process, taking of property by regulation w/o compensation, and violation of the Federal OSHA standards. I'd rate the first two as very weak, and don't do OSHA so I can't size up the last.
One thing does strike me as incongruous. The last theory invokes a statute which extensively regulates how business is carried on. The first two argue that a far more trifling interference with business is unconstitutional.