Someone who engages in rubbernecking, or turning and staring.
Someone or something with a flexible neck.
To watch by craning the neck (as though it were made of rubber), especially if the observer and observed are in motion relative to each other.
One who snoops
The act of snooping
A private detective
To secretly spy on or investigate, especially into the private personal life of others.
To be devious and cunning so as not to be seen.