Lyric discussion by Evie56 

In the early to mid 60's, before it got really popular, long hair was a contentious trademark of hippies. Unlike now, when it seems most boys have a long hair phase, back then you really could distinguish straights from freaks by the length of their hair.

It seems that Crosby, Stills, and Nash felt the pressure to cut their hair, but this is probably more of a metaphor for conforming generally.

"It increases my paranoia/like looking into a mirror and seeing a police car"

Hippies, because of their distinct hairstyles and dress and notorious reputation, could easily be targeted by cops and others straights. Anyone seen Easy Rider? Probably shows the most extreme examples of straight violence against hippies.

So the boys of Crosby, Stills, Nash, and Young definitely had reason to be paranoid. But luckily, the refused to "give an inch to fear," choosing freedom over conformity. And really, that's what made the hippies so great.

but basically, none of that is relevant to the songs meaning..

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