Give a guy a ride, if you can. After all, the next hitchhiker you encounter may be YOURSELF, in need of a ride.
I have been a hitchhiker a few times, and I have picked up scores of hitchhikers. I'd like to make some suggestions, below, about hitchhiking. By all means accept or ignore them, as is your predilection. Your opinions will differ.
Never use mace or pepper spray on someone unless you are in imminent danger of bodily harm. Insults or foul language are not valid reasons for gassing someone: you can go to jail for using mace or pepper spray inappropreately. Theft of property is usually not crime enough for you to assault someone.
The above being said, I suggest that you carry pepper spray or mace for the obvious reason: no matter how well and decient you treat people, a tiny minority will return your kindness with violence and abuse. It is much better for you to apply a debilitating weapon instead of a fatal one. If violence is offered, do not hesitate to mace or pepper spray the bastard: do not threaten: act!
With pepper spray, the violent person is usually subdued for roughly 10 to 15 minutes. Pepper spray in the offender's face will usually stop the most violent berserker from continuing his violence or abuse. Most, if not all, public classes available in the USA that teaches how to use mace and pepper spray will include a film showing the effects of the sprays on offenders: it isn't a pretty sight, but it's a DAMN SIGHT better than you being killed, raped, or worse!