>>918125 (OP)
Hackers (1995) is a very guilty pleasure. I remember actually renting it from the local movie rental store several times to watch it back in the day. I loved the visuals in it, and how every hacker's computer looked and worked differently.
In the climax, the good hackers use acoustic couplers on payphones to hack into the evil corporation's mainframe, then called up a ton of other hackers from around the world to overload it with viruses all at once. It was great. And Penn from Penn and Teller made an appearance.