This was tied in with such cultural landmarks as communes and Woodstock, and lead to quite a few confused young people having as much sex as possible, due to an urge to break old boundaries and rules and explore their newfound "free" sexuality.
Hippie 2: "Yeah, man, what's up?"
Hippie 1: "They're having a protest meeting over on that hill tommorow night. There's gonna be a lot of girls there."
Hippie 1: "Righteous, man."
Random Bystander: "Why do you kids all have sex with each other? There's no commitment anymore..." *shakes head*
Hippie 1: "Hey, man, that's not cool. Free love, man, peace love and happiness!"
Hippie 2: "Yeah, and screw the establishment!"
*Random Bystander walks away*