I used to laugh at when I saw people out in public like at a bar with thier phone plugged in to the wall. My thoughts were dude, this isn't your house, you look crazy, can't you wait until you get home to check your Facebook? But now I see it all the time. I keep a mobile charger with me but I try to stay off my phone when I'm in a public place with friends ect... Turns out it's best not to charge you're phone in public places unless you do in fact have a personal mobile charger. Apparently in places like train stations, airports and hospitals, a thing called 'Juice Jacking' has been happening more frequently. It's just another way for criminals to steal your personal information, like bank account numbers, passwords ect... it's getting hacked all because you needed to charge your phone. This is the kind of thing that happens in places that provide  things like charging stations so plugging a wall charger into an outlet is probably ok.