CHICAGO (CBS) — A group of about 50 transit activists swarmed into the lobby of a Loop bank on Thursday, demanding to know why big banks are being bailed out, while charging sky-high interest rates for loans to public transit agencies.

WBBM Newsradio’s Mike Krauser reports the demonstrators staged a protest in the lobby of the Chase Tower, at 10 S. Dearborn St., demanding to fax a letter to Chase CEO Jamie Dimon.

They claimed transit agencies are bleeding cash, because of exorbitant interest rates charged by big banks to borrow money, while the banks themselves pay next to nothing to borrow money from the federal government. They said, as a result, taxpayers have been losing $500 million a year nationwide.

LISTEN: WBBM Newsradio’s Mike Krauser reports

Amisha Patel, with the group Grassroots Collaborative, said they want Chase and other banks to renegotiate high-interest loans to the city, state, and public transit agencies.

CBS 2′s Mike Puccinelli reports many of the bank employees stood up from their cubicles, and employees and bank customers stood and stared as the demonstrators staged a loud protest in the bank lobby for about 20 minutes.

“The letter basically says that we are outraged … that Wall Street continues to squeeze transit agencies, and the state and local governments that fund them. … while riders continue to face service cuts and fare hikes,” Patel said.

The protesters claimed banks like JP Morgan Chase have been gouging the state for $88 million a year in interest on loans, while paying next to nothing for the bank bailout from the federal government.

“Interest rates are at a record low, so Chase is paying close to zero. Interest rates have never been this low. Meanwhile, the transit systems are paying anywhere between 3 and 6 percent fixed rate on these deals, so you can imagine that Chase is pocketing that difference.” said Elizabeth Parisian, with Stand Up Chicago. “It can add up to quite a bit. Here in the state of Illinois, Chase alone is making $5 million a year off of that difference in interest rates.”

Bank workers agreed to fax the protesters’ letter to Dimon, then security and police gave the protesters two choices: leave, or be arrested. The protesters then took their rally outside, while about a dozen police officers blocked the entrance to keep them from going back in.

But the protesters said they were satisfied their demand to have their letter sent to Dimon was met.

Chase Bank officials did not immediately respond to requests for comment.