Old Internet slang for "Me too!" Derived from the online service but not synonymous; all definitions saying it just means "America On Line" are incorrect. This is dictionary of slang, after all.
Every September, tons of US students flooded onto USENET as they got university computer accounts. They started spamming newsgroups with meaningless replies. Typically they might respond to nuanced, wide-ranging 16- threaded discussion from 5 years earlier, usually top-posting just to say "Me too!"
But they learned the ropes (or got bored and left.)
Then came the Eternal September, when in 1994 AOL allowed its users to access USENET. Then there was a constant flood of newbies, contributing nothing except to say "Me too".
It is all most people ever saw AOLers say.
So, when someone says AOL on Ye Olde Texte-Based Internet, it means "Me too."
Participant 1: The problem with seeing _Ex Machina_ as being about the Turing Test is that it ignores Yudkowsky's later thought experiment.
Participant 2: Conceded, but this is relatively obscure. Despite its problematic inspiration, though, it is not a bad film.
AOLer: ME TOO!