It's unfortunate that people still seem to think Facebook is as private as, say, the telephone. Or the home.
The latest incident occurred Thursday in Australia when a 17-year-old girl was helping her grannie count her retirement savings. No, these savings don't appear to have been in a bank, with online access.
They were at her grannie's house in Sydney -- in cash.
The girl may have quite enjoyed herself because, as the BBC reports, she then posted a picture of the cash on Facebook.
Perhaps she thought this would amuse her friends. It certainly didn't amuse her mother. A few hours later, her mother -- who lives in Bundanoon, southeast Australia -- had unexpected visitors.
Two men, armed with a knife and a wooden club, arrived at her house. What would have suddenly moved them to do this? It may well have been the Facebook picture of the cash.
Her mom reportedly told the robbers that her daughter no longer lived there. Still, the men robbed the house anyway -- of a little cash and some other unspecified items. At least grannie's savings weren't actually there.
It's not clear how the robbers made their way to the mom's home. What is clear from the police report is that the robbers had seen the Facebook photo.
Who cannot be mindful of the police's parting statement on the report? It reads: "The incident has prompted police to remind users of social media to take extreme caution when posting photographs and personal information."