Obsession, loneliness, a tendency to fail at romantic relationships. I'm not justifying it but I think that's basically why.

Attraction?

Delusion

Their own lowered sense of self-worth. A motivated delusion to foster a connection with someone that doesn't want to return the sentiment.

One of countless reasons.

Personality disorder/mental illness

Some form of attraction that makes them disrespect a persons right to privacy.

A disease i wish that had a medicine.

Many reasons jealous, love, revenge, delusional, and desire

Being head coach of Michigan Football

Idk I've never been admired enough to be stalked 😭

Probably there are more reasons.
1. To plan an attack on them or to steal from them for some personal gain.
2. Sadistic pleasure from triggering fear in someone
3. Obsession and a lack of impulse control, often paired with delusion

Want something they can’t have.

They think they're owed someone's autonomy.

Unhealthy attention to someone.

power trip is my guess
the need for control

When desire overtakes reason, stalkers and obsessions are born....

Power, sexual gratification.

The stalkee's delusions of attractiveness and their imagination.