Sometimes I remember the clunky devices of my youth — the boxy Polaroid cameras, the bricklike car phones, the shrill answering machines, the pagers that could be made to spell an angular, all-caps “BOOBS.” This was the personal tech of the early-to-mid-1990s, in the years before AOL Instant Messenger provided an internet on-ramp, which means it was pretty much the last time an American teenager could behave with some expectation of privacy.
Still, camcorders existed back then and Soleil Moon Frye, the child star of “Punky Brewster,” rarely turned hers off. In “Kid 90,” a documentary now streaming on Hulu,
