So I rode into work today, and every time I do I park my bike right outside the window of my office. I work on the second floor, but having my bike in my sight all day makes me feel better about it. There is very little foot traffic through our parking lot, but occasionally people do go by and a lot of people check out the bike. Well just a couple minutes ago someone walked up to my bike with a stride that would have made you think he owned it. He just stopped and looked at it but at one point I could tell he considered sitting on it. Then I got to thinking, what would I do if he did? I'm on the second floor, so it'd take me a minute to get down there. Then I'd have to as nicely as possible ask him not to sit on the bike, but I feel like that might make me seem like a dick no matter my demeanor. So where do you guys draw the line? What do you do to keep people from messing with your bike when you're not with it? and how would you handle catching someone sitting on your bike? When is it appropriate to say "hey, get the f* off my bike" Obviously there are proximity alarms... but they're kinda $$$