I did not know what a STALKER is until I become one. A stalker can sit in a car nearby a persons house for hours straight. A STALKER poisons the victim's WLAN ARP table and sneaks into the person's Facebook account and takes notes about the persons friends and comments. A STALKER observes who visit the person and feel enormous jealousy towards them. The stalkers would make quite good private detectives.
Most notorious STALKERS build a shrine for their victim and plaster the victim's photographs on the wall around the shrine. They are the REAL PSYCOPATHS. More mild cases just write definitions into URBANDICTIONARY.
Me: Oh, fuck. I became a stalker. I cannot help sneaking around her apartment.
Jake: Get over it, man. There's more fish in the water.