An excerpt:

One frigid March morning last year, federal agents raided a factory in this old whaling town, arresting hundreds of illegal immigrants as they sewed vests and backpacks for U.S. soldiers in Iraq and Afghanistan.

Most were shackled and sent to a detention center in Texas, where they faced rapid deportation unless they could post thousands of dollars in bail — money they didn’t have — to buy time to mount a defense.

Then, a mystery benefactor appeared. The anonymous donor ponied up more than $200,000 to spring 40 people from detention.

[Robert Hildreth]

The payments, which until now haven’t become public despite extensive news coverage of the raid itself, came from Bob Hildreth, a Boston financier who made his millions trading Latin American debt. He was "infuriated" at the televised images of workers being shipped to Texas, he says. Helping them make bail is "payback."