Most of us have heard of it already, but it is possible to merge a group with a squad which will result in the teammembers being kicked out of the fractal instance.
Today i have been griefed by this method, while our group has cleared the Reactor fractal and was waiting at the boss for the 5th person in lfg.
An easy hotfix for this (temporarily) would be disabling squadmerging for a group. People would still be able to join squads and a group would just need to leave its current group to rejoin a squad together. This is badly needed as the griefer i have encountered has done this to many groups in lfg (discription of lfg were already things like "screw the merger").
A better solution is having to accept a squadmerge, since squadmerges are a nice mechanic but the current griefing in lfg has made opening LFG while in an instance a scary thing to do.
Also i would like to remind that this thread is not about nameshaming, i myself have screenshots of people admitting it and telling me they are "untouchable", but lets keep the discussion civil and if you have any names / screenshots post them to the support.