I've recently seen lots of people tweeting this supposed newspaper clipping. An olde-timey warning about wearing flu masks. But is it too good to be true? The first thing to do with any image of a text quote is to search for the text. Look, I'm not saying tumblr isn't great, but… I wouldn't exactly trust it as a primary source! That said, tumblr has a neat feature which makes it easy to see where a popular image originally was posted. In this case it appears to have originated at Y…