The Paranoid Android reference comes from Douglas Adams's popular book series, The Hitchhiker’s Guide to the Galaxy.
That Paranoid Android in Adams's books is Marvin, who's bored and terribly depressed because his brain is so incredibly big and powerful that he can never be fully entertained or utilized. Radiohead frontman Thom Yorke has said that the title is a playful reference to the expectation many people have that he's a depressing person just because his lyrics revolve around themes of alienation and whatnot.
Yorke has also said that the lyrics were inspired by a frightening bar incident in which a drug-fueled woman attacked someone.
In an interview with Q, a music magazine, Yorke said, "There was a look in this woman's eyes that I'd never seen before anywhere. Whether that was down to me being exhausted and hallucinating... no, I know what I saw in her face. Couldn't sleep that night because of it. I was in a bar. Someone spilt a drink over her and she turned into this fiend. I mean, everyone was out of their minds on coke and I'm sure it was that. But it seems to be happening to me a lot. Seeing a look in someone's eye and, F------- hell, what was that? Getting me right (reaching his hands up behind him, evidently feeling his spine)... like someone walking on your grave."
Yuppies define OK Computer's primary target. The entire album—though not exactly a concept album—rails against consumerism and contemporary alienation.
The word "yuppie" has become seriously pejorative over the years… but what the heck is a yuppie anyway? The word "yuppie" is short for "young urban professional," and first appeared in the 1980s to describe a class of young, socially liberal, financially conservative, career-advancement-oriented people. Initially the word simply described a class of people, but it has since acquired many heapings of negative connotations. Theressa Kersten of SRI International captured the dismissive essence of the "yuppie" stereotype all the way back in 1985: "You're talking about a class of people who put off having families so they can make payments on their BMWs... To be a Yuppie is to be a loathsome undesirable creature." Ouch. Yuppies have been targeted by artists many, many times in music and in film; some notable examples are Wall Street with Michael Douglas and Charlie Sheen (1987) and American Psycho starring Christian Bale (2000, based on the book written in 1991).