Facebook temporarily blocked the use of Bit.ly links, now you cannot post a bit.ly link on facebook. It sends an error message marking that the link is reported as abuse by users. The existing Bit.ly links are also affected by this. There are millions of Bit.ly links on Facebook and it is pretty sure that this is a technical defect from facebook. As Bit.ly is the worlds largest URL shortner.
Facebook has solved this issue the Bit.l links are working now, though it is not clear as to why the temporary issue with Bit.ly links came up.