People who sit in the single seats on MUNI that have the audacity to cross their leg so that it sticks out into the walkway path.
I am totally fine if the leg is partially in the walkway since some people may have long legs and have trouble fitting into the space provided.
But, no way should the leg be so far out there that I need to swerve to the edge and walk sideways to get pass.
And when you bump or trip over their leg, they get pissed. Well, duh. The leg is so freaking far out there, it would be impossible to avoid.