Thirsty Bus Passengers

It's summer and I've had it with the large paper cups of slushees, slurpies, and other icy cold drinks people are bringing on the buses with them. Not only are they not supposed to do this as the sign on EVERY SINGLE BUS says this but they suck away through straws oblivious to the concerns of those around them that the drink might slop its way onto us next time the bus lurches to a stop or as they get up. I just don't want to deal with the person responsible or the cleaning bill. One woman put a LIDLESS paper cup of some foamy orange drink on the baggage rack and just left it there not in the slightest bit concerned about how the liquid was tilting and about to splash over every time time the bus turned a corner and slowed to a stop. Another passenger put her half filled (half empty?) paper cup of some sweet syrupy sugary thing on the floor. Of course, it fell over when the bus stopped suddenly. The liquid trickled its way across the bus floor towards my feet and bag. I pulled my feet up annoyed. When she got off the bus I told her off and she just glared at me like she had a right to have a drink on the bus and to leave it unfinished on the floor for someone else to pick up. Not a single bus driver has asked a passenger to put the drink away or drink it up before getting on the bus. So I wonder how the bus system thinks the requirement not to drink or eat on the bus is to be enforced. God only knows, that's for sure!