Hippies in 1967
The term hippie (or hippy) is generally used to refer to a member of the counter-culture, anti-establishment movement of the mid 1960s to early 1970s on Earth. (DS9: "Past Tense, Part II")
Roberta Lincoln in 1968
Roberta Lincoln described the confusion of her generation to Gary Seven: raised in the aftermath of the Great Depression, World War II, and the increasingly volatile Cold War, she feared the Earth would be destroyed in a rain of atomic bombs before she was thirty. The repressive environment of fear instilled in them in the 1950s and the tragic deaths of hopeful figures like John F. Kennedy led them to believe that established figures of authority had been lying to them and didn't know what they were doing. Their reaction gave birth to youth counterculture, such as rock and roll, seeking alternatives to the lives their parents had lived. (TOS: "Assignment: Earth")
The 1960s counterculture movement led to several protests against authorities and the Brush Wars of Asia, including the Free Speech Movement at Berkeley. Members of the hippy movement also regularly consumed drugs such as LSD. (Star Trek IV: The Voyage Home)
Henry Starling, 1967
Noted hippy Henry Starling discovered a UFO while camping in the High Sierras in 1967. (VOY: "Future's End") The same year, Miles O'Brien and Kira Nerys, while searching for their missing shipmates, had a brief encounter with two hippies in San Francisco. (DS9: "Past Tense, Part II")
Maury Ginsberg, 1969
In August 1969, the Woodstock festival, the pinnacle of the "hippy movement", was held near New York City. Maury Ginsberg, a tower operator at the concert met his future wife, "the groovy chick with the long red beads", prior to the concert when, after his van broke down, he was picked up in a jeep driven by Quinn. (VOY: "Death Wish")
The punk subculture emerging a decade later was heavily opposed to the hippy philosophy of "peace and love". (Star Trek IV: The Voyage Home)
Sevrin's search for Eden[]
Adam, a "space hippy", 2269
In 2269, the USS Enterprise intercepted and captured a group of humanoids from the stolen space cruiser Aurora, who shared many of the ideals expressed by the hippies of Earth's 1960s, including their will to spread 'brotherly love'. (TOS: "The Way to Eden")