Mind you, they only really prosecute said abuses on public campuses. Private schools have more latitude in what they do and do not permit. Some private, religious colleges, such as Southwest Baptist University in Missouri, do not take government funding even in the form of financial aid packages, just so that they cannot be forced to allow their students to be exposed to the views with which they do not agree.
Public, state-run institutions are a different matter. State colleges and universities are, in essence, a part of the state political machine, and are not exempt from the restrictions set up in the Constitution.
Yet they try.
Probably the most insidious abuse of individual students' constitutional rights are speech codes. These are rules written into the college and university handbooks that delineate what is and is not acceptable for students to say on campus. These speech codes are meant to protect certain segments of the student body from threats and discrimination. However, many of the codes are so broadly written as to ban anything that is not "acceptable" to the administration and the minority action groups.
In case you were wondering, the University of Delaware's resident life "treatment" program was an outspring of this.
Many speech codes include provisions for what is known as a "free speech zone," usually a small area on campus that may or may not be easily accessible, public, or large enough for more than a dozen people at a time. Usually, these are outdoor venues, which severely limits their use from the outset. And sometimes, some universities decide to bar all outdoor protests, like San Francisco State University attempted to do recently. (Of course, they backed off from this position almost immediately when the FIRE wrote to them and alerted them that they were being watched.)
The FIRE has, in the past, been forced to defend student beliefs against even more egregious abuses than these: the University of Delaware barred a student from campus, pending psychological evaluation, because of things he had on a personal website. Students majoring in Teacher Education and in Social Services often are asked to pass a political litmus test, saying that they support social justice above their own beliefs, to graduate. Such stories are far too numerous in the FIRE's archives to link to.
This type of unconstitutional abuse has no place on public campuses. Especially not when said campuses brag to the public that they support the free exchange of ideas by students and faculty.
The examples I've cited above, as well as others too numerous to mention, imply that they really are for the free exchange of ideas, all right. Just not all ideas (especially ideas that contradict their personal political beliefs), not everywhere, and not all the time.