I covered the Tory Party Conference a few years ago, for a paper I did an internship with. There were many instances of delegates eating in restaurants and leaving without paying. People being appalling to waiting staff. Paying with 50quid notes and eating up float in shops. This is what happened.
The kitchen staff in hotels and restaurants across Manchester started keeping bottles of piss in the kitchen and dousing the food of the worst offenders.
Be nice to people. Especially those who have access to your food and your room, dont display your lanyard too prominently in the street, and don’t think anyone is looking for your approval. You might be fine. If you cant do these things, only eat prepacked food.