​Twitter user Hidden Cash is stashing money around SF

Who is "Hidden Cash," besides an anonymous Twitter user? For one, he's already gained more than 60,000 followers in only four days, thanks for his habit of hiding envelopes stuffed with cash around San Francisco.

Other than that, the do-gooder tells the San Francisco Chronicle that he's a man between 35 to 45 years old, who recently made a profit of "about half-a-million dollars." In an email to the publication, he added, "I decided even before it closed that one of the things I wanted to do with the money was something fun in SF."

Most importantly, he says he has "no plans to stop anytime soon."

The mystery man's M.O. works like this: He stuffs envelopes with bills and then tweets hints about where he'll hide the stash. One recent hint read, "New Drop: 'Life is a beach .. and I'm just playing in the sand,'" accompanied by a photo of a beach scene.

An hour later, Twitter user Forrest Hanson wrote that he had found the stash at a beach location, and that he had shared the cash with other beach-goers.

From Thursday to Sunday, he has given away $4,000 in cash, according to USA Today. Hidden Cash didn't immediately respond to an email from CBS MoneyWatch.

While his hidden giveaways have gained thousands of captivated fans in San Francisco, he's apparently planning to spread the wealth to other cities. On Sunday, he wrote, "@HiddenCash is going nationwide! Let your friends around the country know," adding, "Next wknd: LA." He also wrote that he plans to hide cash in San Jose on Wednesday.

So what's his motivation? He told the Chronicle that he picked the idea of money drops because of its simplicity.

"I played around with different ideas, and frankly, they were too complicated," HiddenCash said. "I was thinking of a 'Survivor'-type game...or something like it at some point."

He added that he's not likely to reveal his identity. "There are a few reasons I would like to keep my privacy," HiddenCash told the publication. "One, some people close to me wouldn't like that I am giving money away. Two, I enjoy having my privacy. Three, (I) had some publicity before and nothing good ever resulted from it."

And Hidden Cash also shared his motivation with his followers, noting that he also supports "many charities" as well as hiding the cash-stuffed envelopes. The latter, he wrote, "is for fun."