"Every Bit help," reads the sign, which includes a QR code.
WHAT IS BITCOIN?
Bitcoin was created in 2009 as a virtual currency free from government controls. Its value surged from about $10 to more than $1,200 in late November 2013.
While it's slowly gaining commercial acceptance, Bitcoin is notoriously connected to the sale of illegal drugs on the Silk Road online black market. Last year, the FBI shut down the Silk Road and seized 144,000 bitcoins worth $28.5 million.
Overstock.com was the first major online retailer to accept bitcoins as a form of payment, and the NBA's Sacramento Kings became the first major sports franchise to accept bitcoins for game tickets, merchandise and concessions.