Lawmakers made it clear at a Senate Banking Committee hearing on Tuesday that they believe the biggest roadblock to Facebook’s plan to enter the world of cryptocurrency and global finance is the company’s reputation.

Facebook’s cryptocurrency project, Libra, has been in the works for more than a year. It has an ambitious goal: to offer an alternative financial system that makes it possible to send money around the world with few fees.

But almost immediately, the company has run into resistance from Washington.

“Facebook is dangerous,” Senator Sherrod Brown, Democrat of Ohio, said at the hearing. “Facebook has said ‘just trust us.’ And every time Americans trust you, they seem to get burned.”

The initiative is far from the first effort of its kind. The best-known cryptocurrency, Bitcoin, is in wide circulation, and it introduced the idea of digital currencies that are free from government control.