I consider the use of MNTA's patented IP to be stealing - if it's not, then what is the use of a patent?
'Steal' implies industrial espionage and/or willfullness that probably is not there - for instance MNTA's patents weren't even published until 2009 and 2010.
I would think that the FDA doesn't look to kindly to Momenta's IP when trying to protect others from entering the generic field. In many ways I'd say that the FDA will do everything possible to circumvent Momenta.
The main thrust in bio-generics is not to only allow one generic competitor for each drug.