Not gotten arrested per se, but I did have a rather interesting encounter with the police once... One dark and stormful night... Except, it wasn't stormful at all and hardly dark. Clear skies and a nice large moon. Great for riding home on your bicycle!
Or so I thought... Until... The police asked me to stop. Now, at the time, it was winter, bloody cold and it was well below freezing when I was heading home. I was wearing my skigoggles (I wanted something that could shield my eyes in general and also from the sun and I think I look an absolute twat in sunglasses), my necktube/neckpipe/long-tube-of-stretchy-woolen cloth-to-keep-your-neck-warm-thing over the lower part of my face, a beanie, the hood of my jacket, black pants, black leather gloves and my boots... Which are also black. I can't really blame them for thinking I looked like one sketchy mofo. Well, after they more or less flashed me in the face with the big freaking lamp they got on their car, I pull over, they direct me to go back a bit so they can park their car in a spot that doesn't impair traffic, get out and asked me who I was and what I was up to. "Going home, officer... Why?" "Please, remove your mask" And I did... And they stared weirdly and asked "Are you one of the roleplayers?" "Yes, I am" "Oh, sorry about that, then, but do try and keep your face somewhat visible".
How did they guess I was a roleplayer? Easy. I had just come from a LARP, my face still full of green paint from being an orc. The police knows us and know that while we can look freaking dangerous (We can field at least 2 guys in plate armor if we want and about seven other people in anything from mail to leather armor), that we are essentially harmless.