AFP - Getty Images Stock On Thursday, a teenage girl posted a photo of a "large sum of cash" on Facebook. About seven hours later, two robbers arrived at her family's home. Unsurprisingly, this incident prompted local authorities to issue a warning about the dangers of posting photographs online. According to BBC News, the 17-year-old girl was helping her 72-year-old grandmother count her cash savings when she decided to snap a photo of the money and post it on Facebook. A press release by the local police force explains that this social media activity occured in Sydney, Australia at about 4 p.m. on Thursday. At 11:30 p.m. on the same day, a house about 75 miles south-west was invaded by two armed men. The girl's mother, a 58-year-old man and a 14-year-old boy were home at the time. Brandishing a knife and a wooden club, the two men "allegedly entered the home demanding to speak with the girl about the cash" seen in the Facebook photo. After the girl's mother explained that she no longer lives at that address, the men proceeded to search the house and "took a small amount of cash and other personal property before leaving." It is unclear how the robbers connected the girl's social media activity to her mother's home address, but authorities are nonetheless urging "users of social media to take extreme caution when posting photographs and personal information." I suspect that's a polite way of saying "Use some common sense, folks!"