There is a very straightforward answer to this sort of behaviour ? Withdraw the services and have the timetable operating around a 6am to 6pm 12 hour timeframe. Controversial yes but putting lives and vehicles at risk for the few measly quid in revenue they generate ? Is it worth it ?

Come the day and the fast escalating Corona virus situation though are we going to have buses for these mindless imbiciles to terrorise ! Now that is scary !