Yesterday, a YouTube video (since removed) purporting to contain information about the next Skyrim DLC was put up on Reddit. It received hundreds of upvotes in mere hours and got many people to believe that Bethesda was working on a DLC titled Redguard. It was fake.
The "proof" in the video consisted of a Steam page with information about the DLC, containing screenshots of armor from the Immersive Armors mod and the Redguard Knight Armor mod, as the more skeptical of reddit's keen-eyed readers discovered. If you fancy playing a Redguard, then picking up either of these mods might not be a bad idea—but they're far from what you'd expect in a full-fledged DLC for Skyrim.
Another big tip off was the fact that the DLC was stated for release on June 9, 2013—a Sunday. Most games, including DLC, are released on Tuesday.
The hoax is just one of many. If you've ever wondered about these fake screenshots are created, it's pretty easy. Just right click any element in your browser and select "inspect element" and you'll be able to edit the HTML from the raw code. I've made my own example below.