Enlarge / The Ebay Inc. Venmo application (app) is arranged for a photograph on an Apple Inc. iPhone 5s in Washington, D.C., U.S., on Friday, Aug. 22, 2014. (credit: Andrew Harrer/Bloomberg via Getty Images)

I’m a regular Venmo user. I used the service a month ago to receive $30 from my sister-in-law. I used it again two weeks ago to reimburse my brother after we threw our father a surprise birthday party. It’s a perfectly useful service.

But unlike most Venmo users, I have my transactions set to “private”—and I’ve never understood why the default setting was “public.”

Why would I want the world, even my Internet friends, to know when I settle bar bills? I know of no mainstream payment system that makes its transactions public. PayPal, Venmo’s parent company, doesn’t even do this. After new scrutiny last week, Venmo still will not explain fully why the public default is useful.