Where's the evidence Facebook is using it for a revenue source?
A hung trial is closer in meaning to not being found guilty or innocent.
Arguably, a semantic difference does apply in that you may still be found liable in a civil case. However, civil cases don't declare people guilty only liable.
Incidentally, this is largely why Scots law verdicts of acquittal -- "not guilty" and "not proven" -- reflecting the two standards of not guilty. "Not proven" carries the implication that the jury is not convinced of the defendant's innocent, but there is not enough evidence for conviction.