Remnant Gaming News has published a short Star Trek Online interview that was conducted with an unnamed source over at Cryptic Studios. There isn't much information to digest in this particular Q&A, but here's a quick excerpt anyway:
RGN: How is (kill stealing) being addressed in STO? Is there some sort of (tagging) system in place or planned? Will it be a factor when in combat with other ships not in your group?
Cryptic: The way the game works, you tend to get more rewards for completing objectives within a mission, and the majority of the time you're in one specific place, everyone has the same mission, meaning someone (kill stealing) you is actually just helping you progress through whatever stage of the mission you're working on. That's definitely a major benefit of the instancing system.