I had a friend once who admitted to me the extent of her stalking behavior on the guy she was basically a booty call for. She had so many sophisticated ways to get his passwords, PIN numbers,etc. She convinced him she was ok with the nature of their casual sexual relationship while he actively sought other women to date. She offered to water his garden while he was out of town so got a key. She once confessed it all to me saying " there is not one pocket of any article of clothing he has I've not gone through, not one drawer I don't know exactly what's in it". She admitted going through all his emails and private computer stuff regularly and emailing women he was trying to date. I was shocked she confessed all of this and just said "you know you need to get help here". She had zero remorse and shortly after confessing all of this went crazy on me after seeing a friendly post about food or something I made on his FB page and broke off our friendship (whew!). I promptly told him, quietly and privately, that he needed to change all his passwords and PIN numbers and get his locks changed. He was my friend first but she befriended me like she did all females close to him to glean info (didnt realize all this til it blew up).
She had no problem either sneaky watching him sign on his accounts or find ways to ask him for keys etc just to get the access.
So so sick. This was years ago now...she also always said they would always be friends. He's in a serious relationship now but I doubt her obsession is gone 100%. They have no contact though. I have nothing to do with her either, thank God.