Starbucks will be trialling new methods to get rid of certain customers that frequently visit the coffee chain. It's gone as far as installing panic buttons for staff to use, reports claim. The billion-dollar company continues to crack down on customers who sit in its shops or try to use its toilets without buying anything. Workers in the United States have been given new guidelines on how to eject customers who attempt to use the toilet or fill up water bottles without making a purchase.