CHICAGO – Chicagoans scurried around the city's lakefront Sunday looking for envelopes of hidden cash, then posted photos of their good fortune on Twitter.
It was all part of Hidden Cash, a scavenger hunt craze started in San Francisco by real estate investor Jason Buzi, who says he's one of several people behind the effort that he calls a "social experiment for good."
The altruistic group encourages people who find cash to pay it forward by doing something nice for someone else.
Buzi has said many have responded by spending the cash on coffee, groceries or gas for others or by helping the homeless and charitable causes.
Hunters followed Twitter clues to find the envelopes, some of which were placed in statues in Millennium and Oz parks. Hidden Cash also tweeted that there will be "a small surprise" on Monday, hidden in a different Chicago location.
The scavenger hunts started in San Francisco and have been spreading to other cities, including New York, Houston and Mexico City on Saturday and Chicago on Sunday.
The altruistic group also plans events in London, Paris and Madrid in the next two weeks.
Hidden Cash has inspired similar, unaffiliated cash giveaways in St. Louis, Boulder, Colorado and other cities.