As seen here (p.13), the Department of Public Safety at UM-Flint defines stalking as:
1) Engaging in a course of conduct directed at a specific person that would cause a reasonable person to fear for the person's safety or the safety of others; or suffer emotional distress
2) For the purposes of this definition:
Course of conduct means two or more acts, including, but not limited to, acts which the stalker directly, indirectly, or through third parties, by any action, method, device, or means, follows, monitors, observes, surveils, threatens, or communicates to or about, a person, or interferes with a person's property.
Substantial emotional distress means significant mental suffering or anguish that may, but does not necessarily, require medical or other professional treatment or counseling.
Reasonable persons means a reasonable person under similar circumstances and with similar identities to the victim.
(MCLA 750.411h).
As seen here, the University likewise defines it as:
Any unwanted contact between a stalker and their target of a sexual or romantic nature that directly or indirectly communicates a threat or places the target in fear.
Examples: following a person; repeated and unwanted telephone calls; making repeated and unwanted contact by email or on social media sites (e.g., Twitter, Facebook); or leaving gifts for their target.
As a general rule, if it makes you uncomfortable and you are unsure if it is "serious" enough after reading these criteria, talk about it. Confide in a friend, a professor, or a counselor that you are encountering uncomfortable behaviors.
Often, seemingly innocent habits or coincidences, such as someone frequently showing up in the same places as you without a need to be there, can gradually escalate to more threatening behaviors. Because this happens gradually, it is difficult to discern whether there is a threat or not.
If you encounter a situation in which you believe you are being actively followed, or encounter aggression or disturbing behavior, you should contact campus security and report the situation. You may elect to be accompanied by a campus officer if you feel uncomfortable walking alone.
Prioritize your safety.
Non-physical stalking also occurs. If you feel that someone is collecting unnecessary and uncomfortable information or media about you, specifically finding and/or harassing you via online social media accounts, sending you threatening texts or phonecalls, or otherwise making you uncomfortable through digital means, it is possible you are being stalked.