Dark energy can escape black holes.

[Richard87]

http://curious.astro.cornell.edu/question.php?number=760

Yep, it's an exception to the rule that "nothing can escape a black hole".

 

[Wallace]

Hmm, that's a pretty badly worded article I'm afraid. For starters it doesn't define what it means by 'escaping from a black hole', but for any meaningful definition, dark energy is not immune to being accreated onto black holes. For a random article discussing this see http://arxiv.org/abs/gr-qc/0502118" but that's just the first one I found doing a simple search. In general dark energy will be accreated onto black holes, except for some special cases.

The rate of accreation is quite small though, so most of the mass of black holes would have come from other forms of energy rather than dark energy.