What happened to "thank you"?

[Matt Meiser]

In this day and age, leaving the bike out may have sent an unintended signal to the receiver, like "just take it and be gone". There is a lot of craigslist paranoia, so they may have assumed you'd rather not talk to/ meet them because, you know, serial killers are known to want free bikes all the time.

This was my first thought too.

[Al Launier]

Any person unappreciative of your generosity, who can't even thank you, certainly doesn't deserve the bike. You could call the phone number he used to call you to find out who he is, if you want to, just to say "you're welcome" to get your point across.