To be clear, no one is suggesting that Universities should be "policing every dispute." I am stating that Universities can and do seek to create the most effective learning environment for their students--and that harassment undermines this goal. This is why Universities, as indicated in the article, blocked (aka geofenced) YikYak (& though it is not mentioned, other apps as well).
Not sure I understand how that's relevant, but most University rules are not laws--but, while breaking them may not be criminal or even illegal,it can still get you thrown out of school.