There are a few things I know about plagiarism in high school. It's rampant. High schools tend to be pretty lax about it--it's seen more as a teaching opportunity than a reason to destroy someone's yet-to-begin career. Teachers warn that colleges are much more strict and you better learn your lesson or there will be dire consequences.
But how often do we hear about someone suffering dire consequences from cheating in college? Rarely. The "things will be more strict in college" threat seems about as empty as the "this will go on your permanent record" threat. How exactly do colleges treat plagiarism? The answer isn't simple. It depends on the circumstances, the school, and the professor. It's very subjective and case-by-case.
So here's a story about an actual case of plagiarism and the consequences. It's by no means the only way that plagiarism gets treated, but I think it's fairly typical.