Continuity mistake: When Joey gives the disk to Phreak, he puts his hands down while Phreak still has his hand up. The shot cuts to the surveillance agents and Phreak's hands are both down. (00:59:00)
Plot hole: If Dade is 18, like we find out at the beginning of the movie when his mom says happy birthday, then his probation is over (the judge said "until the time of your 18th birthday") and the terms restricting computer and phone usage no longer apply. The threats by Secret Service about violating his probation are BS since he's not on probation anymore.
Continuity mistake: After Dade and Kate go into the bet, Dade is seen writing notes and passwords on his notebook with a pencil. In the close-up, you can see everything he'd written down is in blue ink.
Plot hole: To play a practical joke on Dade Murphy and other new students, they are told, "There's a pool on the roof." The victims accordingly go there and are trapped by the roof access door being one-way until – we don't see how or who frees them (Janitor? The least-mean of the prankers?). How do the new guys get onto the roof in the first place? I should think that the aforementioned access door would be locked to prevent it.
Suggested correction: Compared to half the mischief they cause, picking a lock is easy. I, myself, learned how to jimmy my middle school's door locks with my student ID and accordingly let myself in, and even did so in the sight of other students. It's only because I lacked their level of will for mayhem, their imagination for excuses, and, more importantly, their level of powerful parents to perform legal rescue, that I stopped doing so before the teachers got suspicious.
Suggested correction: This is in the form of a question. You can assume they lock the roof door, but they don't have to. Or, the person tricking them has unlocked the door for the prank. Or, they picked the lock. Plenty of possibilities, I'd say.
Character mistake: When The Plague starts talking at the meeting and comes up with the story about a hacker planting the virus, he first says that an "unknown intruder" was the one who broke in, but only minutes later says that the cops picked up him already. (00:34:40)
