Suppose Shmeryl regularly and unabashedly eats at McDonald's (not the Kosher one in Israel!), or engages in some other unambiguously un-Halachic behavior. Shmeryl doesn't believe that there's anything wrong with this or that there's any reason to hide it. Assume that Shmeryl is not a public figure.
If Shmeryl's friend Beryl, in the course of a public internet conversation, wants to mention what he heard about McDonalds from Shmeryl, may he? Does it matter whether he mentions Shmeryl's name? Assume that there's no pressing need to mention this information, but it's useful in the conversation.