I've been seeing bubble titans use spike void nades to kill people running GMs on the Cosmodrone. I just spent an entire run of Ketchcrash looking over my shoulder because I asked (firmly, but politely) a Thundercrash Titan to quit shouldercharging me, and I was targeted the rest of the activity. If there is a way for Bungie to disable any kind of player-on-player interference in PvE, this would greatly decrease the potential for toxicity within the community. Actions like this are not sanctioned and are not okay, but there's nothing you can do except look out for it and avoid it. I'm not a dev, and I don't know if this is even possible. But to ask people in the community to quit interfering and sabotaging other players is unrealistic. I would recommend a full disable of player on player interaction in PvE activities. It's not fun, and all I can do is avoid it or retaliate. I don't like the second option, and the first one makes the game unfun.