Back in August, the Daily Mail published an article about Melania Trump's racy modeling days. In it, they basically claimed that she had once worked as an escort.
While it's true they didn't explicitly state the allegations were fact, they rode a knife edge, repeating rumors and shoveling slimy innuendo in such a way that readers were left with the impression that such accusations were probably true. The story was picked up by a variety of outlets, but was immediately denied by the Trump camp. Within two days there were rumblings of a lawsuit and several websites, including Inquistr, Bipartisan Report, and Tarpley.net backpedaled.