SACRAMENTO — Once viewed by some as the virtual plaything of techno-nerds, bitcoin today can buy a BLT. The cryptocurrency can secure new sneakers, get a gift card and, yes, even retain a lawyer.

It’s not exactly mainstream yet, but bitcoin is far more widely accepted in commercial transactions than when the peer-to-peer money system emerged seven years ago. And that’s raising all sorts of novel legal issues, including one at the center of a federal court hearing this week.