Suburban Curtain Twitching is the act of standing in wait at the uppermost window in your domicile, and awiting for people to walk past so as you can give them a bad look, and hopefully be able to call the police if they are acting strange or dodgy in any way.
This type of activity is normally found in suburban areas, and most commonly of all is practiced by either old people and middle-aged men.
*Walking along a street, you look up at a window and notice that two of the curtains are slightly parted, letting someone peek between them. You point at them and tell your friends*
"Look at that Suburban Curtain Twitcher, the scum thinks we are up to no good"