XBOX released a statement about 10 minutes ago that Online Gaming and Core Services will be limited for a while. Apparently, Titanfall has caused some major issues overall. Between issues joining online games, to signing into your profile in general, the XBOX team is said to be working on an update which will be released in 30min-1hr.
Page where I found this: http://support.xbox.com/en-US/xbox-live-status
-Kid