Cretins will rob you on Muni buses, in library bathrooms and on bustling downtown streets, as evidenced in San Francisco incidents Wednesday.

Mission and 17th streets
8:30 a.m. Wednesday
A 60-year-old woman was robbed at knifepoint aboard a Muni bus. One of two teenage punks rifled through her pockets as they pressed the knife against her clothing. The only thing they got out of it? Her garage door opener.

Arballo Street and Vidal Drive
9:20 p.m. Wednesday
A 25-year-old man said he was waiting for his pal when a thug he didn’t know shot him in the leg. The injury was not life threatening and there has been no arrest.

Diamond and Chenery streets
5:30 p.m. Wednesday
A juvenile was attacked in a library bathroom. The suspect, a man in his early 20s, crept up behind him, covered the victim’s mouth and stole his cellphone from his pocket.

Montgomery and Washington streets
6:35 p.m. Wednesday
A 20-year-old man snatched a 30-year-old woman’s phone and ran but was chased down by good Samaritans. The phone was recovered and the suspect arrested.

maldax@sfexaminer.com