I'm pretty sure party A, C, D, E,... would react pretty nuclear before B went on its merry way.

This is not piracy in the middle of deep space. Your merry organisation needs to simultaneously launch a force of commando's, their weapons, trained starship crew, colonists, and at the very least minimum supplies into an intercept orbit.
Then it needs to board its prize, take it
completely unscathed, and load the non-military component while spacing the original crew&colonists.
To top it, they need to secure cargo for acceleration, hibernate their colonists, figure out likely unknown details about ship systems, warm up the propulsion drive and be on their 'merry way'.
I don't know about you, but that sounds like an operation that needs a couple weeks to accomplish once the shuttles launch. Plenty of time to sent a few nuclear-tipped missiles on an intercept course and be done with it.