Most of my addons are gone...?

So, I noticed about 3 days ago, most of my addons were gone. This includes maps, addons, you know.
Basically, I went from about 13 pages of addons, to about 3. But they’re all in my addons folder. Anyone know what this is?

http://forum.facepunch.com/showthread.php?t=1377718
http://forum.facepunch.com/showthread.php?t=1378361
http://forum.facepunch.com/showthread.php?t=1378310
http://forum.facepunch.com/showthread.php?t=1378265
Visit one of those threads, this has been asked like 500 times already.