Seriously, I've seen a lot of famous people or not necessarily famous but people with respectable fan bases, be it an actor, a musician or whatever, who seem to be so displeased with people walking up to them, screaming and overreacting in general. It's obviously an annoying thing but still, all these people don't even know you and yet they care about you and you're making them happy, so why is it such a bad thing? I'm sure that most popular people were unknown at certain points in their lives and they'd have killed to meet someone they idolized themselves.
Because really without fans celebrities wouldn't be what they are. At the end of the day these are the people who are putting money in your pocket. Everybody wants to be appreciated, paid well, and to share his work with others; so why bitch about it once you have it? I'd say it's a small price to pay for what you're getting in return, and let us not forget that celebrities do want to get it, otherwise why wishing for a role in a big movie or a multi-platinum selling album.
And yeah, it'd be more appropriate if the fans wouldn't overreact but these things aren't so easy to control. We all here can plan a meeting with Em but I'm sure all of us would lose our minds if we ever come in contact with him. Knowing that a picture or a simple "Hi" can mean the world to my fan I seriously doubt that I'd act as a douche if I ever get in such position. In fact, if I was Em I would be posting in here right now and skyping with you motherfuckers just to make you happy as fuck. And this is why I really respect Hopsin, who is one of the few people I know openly inviting fans to greet him. And Vin Diesel too, who would read countless facebook comments and reply to random people just to show that he cares (and hence him having so many likes on fb).