Here's a not-so-common scam...
My friend (seriously my friend - not me!

) is selling his bike and some dude checks it out & wants to test drive it. Ok no problem, right?
The guy rode off & never came back!! My buddy actually found it funny.
Lesson for anyone who is selling their bike on Craigslist:
1. Put a long leash on the guy's neck as he rides off & pull back if necessary

Jk!
2. Hang on to their ID or wallet as they test drive (works best)