I'm not sure that facebook does it for the "promoted" text, but they have been known to mess with layout to make text difficult to detect. For example each char

I'm not sure that facebook does it for the "promoted" text, but they have been known to mess with layout to make text difficult to detect. For example each character of a word might be in a separate <div> and be strangely offset so as to line up. The divs might not have the mutually common parent element that you would expect.