Speaking in Tongues in Public? What Does the Bible Say?

Michael Rowntree recently posted a short addressing Deion Sanders speaking in tongues at a press conference, and pointed to Paul's instruction that tongues shouldn't be spoken in the congregation with an unbeliever present unless an interpreter is there too, so the unbeliever isn't left thinking you've lost your mind (1 Corinthians 14:23, 14:27-28). Comments came fast: isn't there a difference between tongues spoken publicly in a church service and a private prayer language used to bui...