All around the Bay Area people are finding cash-stuffed envelopes, and now the search is on for the millionaire behind the giveaways.

The mystery man set up a Twitter account, @Hiddencash, and is asking those who find the cash to respond by tweeting a photo.

The person, who calls the cash drops as "an anonymous social experiment for good," is tweeting out clues on where to find the envelopes:

A man named Matt Burkurt ended up finding one of the $100 envelopes on an abandoned bulldozer after seeing the clue above

Here's another lucky recipient:

The man says he's a successful real estate investor between 35 and 45 years old, but so far, he is going to great lengths to remain anonymous. More than $4,000 has been given away since Thursday and more drops are planned for Wednesday in San Jose. The man also plans to do the same in L.A. and New York.

Check out William La Jeunesse's report above from America's Newsroom.