eagletrek hit the nail on the head. Situational awareness is one of the FIRST item of thought for anybody who trecks the (sub) urban jungle. Police and military teach this! Awarness of your surroundings, who's there (who's not there) Etc. People walk into buildings, heedless of the best/closest exits, more often proneto the door they came in if a fire breaks out. Who's sitting in that van over there in the parking lot near your car? Whos in a city park doing playing B-ball or skateboarding or who's obviously looking for something
We may be eyeballing our GPSr more so than the group of miscreant morons who watched you pull up and fumble with equipment.
The debate of defending oneself with lethal or non-lethal force is moot- have you been trained to use a weapon in a combat situation? Do you understand the laws regarding this issue in your community?
Every situation is different, there is no cut and dried solution to what options you have when faced with what happened that started this thread.
Being aware of what is going on is the first line of defence.