Ive had warnings from the police when i was on a dirt jumper doing trials but never when I'm on a proper trials bike , they just say get some lights and why don't you go off road and tell me i going to get fined if i get court again. so to me what that means is don't get court ! as soon as you see the police just ride off , that's all they want is for you to leave, then you can go back another day . As for civilians they are split i half some really like it and watch whilst you give them a demo and others give you dirty looks and ask you questions like "Do you want the bill for that "