I've asked several people in game, and have yet to get an answer.
In PvP, every so often when I attack someone, they return fire with what looks like a blue pulse cannon. But, the problem is... it completely ignores shields. It kills me faster than anything I can do anything about it.
One person suggested that it was Reverse Shield Polarity... but that doesn't make sense. The Reverse Shield Polarity skills that I use all say that it converts energy damage to shield power... it doesn't reflect it.
Feedback Pulse is a Science bridge officer ability (Lt slot for Feedback Pulse I). Only reflects beam weapons back to source, and currently straight to hull (ignoring shields). Reflection damage modified by AUX power, Deflectors and Deflector Fields.