What for just being generally friendly to people or for going obnoxiously out of your way?
If someone sues me for just being generally friendly and courteous they will never see me in civil court

I dont care they can send me to jail for not showing up to court.I will tell the judge that he is an idiot right in court for allowing such a case I really do not care and I will have a great big smile on my face.
See that is what is wrong with the world people dont want to step up to the boot that is pressing their face into the dirt(which may be their own doing in many cases) so they treat everyone like crap and have a negative attitude because they are afraid to challenge the way things are that are making them feel so negative in the first place.The ultimate coward in my opnion the one who knows what the real problem but does nothing about it.
I am not saying you need to go around and seek out those who look gloomy and nag them about smiling that is annoying.But maybe if people were not so busy being mopy about their lot in life when they should be glad that they have what they have in the first place when many others wonder where the next meal is coming from.Maybe if they just gave a general greeting or nod to people they pass by on they might actually feel better.