When player A enters the bubble of player B or visa versa both players will get a broken red chain.
This chain can easily be used as an indicator of enemy presence.

Myself I have used this accidental indicator to change my direction to get an overlook on the intended destination.

With some game play I would say that the radius is about 1k or 1.2k.
knowing this gives quite an advantage when approaching an area that has 1 main obj in that radius.