Haight residents hoped that the influex of needy newcomers would slacken as the Be-In faded from public memory. That possibility was lost in early April when Paul McCartney popped into the neighborhood for a quick look at a place whose reputation as a hippie haven had spread all the way to England. McCartney apparently failed to take in the piles of trash and milling herds of ragged misfits. Instead, he pronounced that Haight hippies were collectively "colorful and fun," and his comments made fresh headlines. A Beatle had endorsed the Haight. That encouraged still more people to come, and among them were hardened dealers sensing limitless profits from a growing mob of consumers who believed it was their social and spiritual obligation to ingest drugs. Owsley [Stanley] still controlled most of the LSD market, and marijuana was smoked in the Haight as often as conventional cigarettes. But these new pushers offered hard drugs -- heroin and Methedrine and other chemicals encouraging harsh hallucinations and physical violence. Haight arrivals, and not a few longtime residents, proved indiscriminate in what they took and how often. Using syringes became commonplace on the Haight's sidewalks. The hard-line dealers wormed their way into the community and swiftly became as integral as the [free-food providing] Diggers.

-- from Jeff Guinn's The Life and Times of Charles Manson