It seems to be that the term 'stalker' no longer means what it used to mean--the pathological ANONYMOUS follower and tab-keeper of another person or persons (A detective who has not been hired and has no real reason to follow someone). The old definition also would say that a 'stalker' often has an imaginary connection with the stalkee.
HOWEVER, common usage of the term, along with the term 'creepy', has come to be used as a defense mechanism for anyone seeking justification for not being attracted socially or physically to someone else.
This term is nearly as overdiagnosed as ADHD is in children. Any women who think an undesirable man might be interested in her will almost always automatically label him a stalker.
Note: Far too many idiots think they're more important than they really are. Real stalkers seek out beautiful, interesting, and often famous members of the attractive gender. 90 percent of the people who use the term couldn't get a real stalker to save their lives.
A hot girl who follows you around and shows up at your door is a friend.
An ugly girl who follows you around and shows up at your door is now, according to most, a stalker.
A hot guy who gives you flowers is a romantic.
An ugly guy who gives you flowers is a stalker.