Sometimes people have an addon that spams to 'kill black', and what usually happens is half the group goes red and half green. Then there's a big argument from the people who went red about how "green doesn't do anything" (huh?) , "LFR is different to normal" (while that person is themself oblivious to how green works) and the people who went black complain about everyone else not following instructions.
In the end what happens is no blob dies, the group kills the boss anyway because the damage is so low, and then everyone stops !@#$%ing eventually.