User blog comment:Reptileman778/What is the canon explanation for why you are fighting geth in multiplayer?/@comment-4953843-20120910172117/@comment-2250460-20120910192715

Thats still doesn't make any sense though, with Legion's sacrifice all geth stopped hostilities, why why would some continue to serve the Reapers after the code has been distributed and the Reaper on Rannoch was destroyed.