Romantic scandals have been around for centuries, but it was often difficult to get the details of said scandal before the internet. That's why people would take it upon themselves to seek out young couples who were in public and watch for any signs of scandalous activity.
Rear Window was definitely about a Munz-watcher!
Those people were called Munz-watchers. A Munz-watcher is "One of those sneaks that make a practice of watching the movements, etc, of sweethearts on their nightly walks, and if any impropriety is witnessed, demanding hush money to keep the matter secret." (The English Dialect Dictionary, 1903) Sadly, the only thing I could learn about this term's origins is that it's from the early 20th century. But, lack of origin aside, Munz-watcher is still a relevant word. In fact, you've probably been one. With the invention of the internet, and later Facebook, being a Munz-watcher has become much easier. We can now actively stalk and spy on people we know (or don't), and discovering scandalous activity can be as easy as sorting through their status posts. If something truly scandalous is found (like your friend Joe flirting with someone other than his wife), a simple private message is all you need to solidify yourself into the role of Munz-watcher. Now, I am not condoning this type of behavior. Being a Munz-watcher will not make you rich, so please don't go looking for people to blackmail. I merely think it's interesting from a writer's point of view. Having one of your minor characters be a Munz-watcher could affect the overall story in ways you'd never expect. For example:
"Did you hear about Lena kissing Rolf last night?" "No! Isn't she engaged to Michael?" "Yes! Charles saw the whole thing." "Charles? Isn't he the local Munz-watcher?" "I never thought I'd be a Munz-watcher." Hannah thought to herself as she quietly watched Princess Elaine kiss the castle's stable hand. Leo typed furiously on his computer as he composed his message. "Joe, if you don't give me $1,000 by tonight, everyone will know about your two girlfriends." "This is it!" He smiled as he waited for a reply, "This is the day I officially become a part of the Munz-watcher's society."
As you can see, there are plenty of ways to use Munz-watcher in your writings. Just be careful of the consequences! To learn more, visit Mental Floss and Stylist. The photo came from The Film Spectrum.