Autonomy is the right to self govern or in simple words do what or as you please. Bbs is giving us the autonomy in the sense that in here we are free to post content according to our own thinking as long as it follows the rules and at the time of our own choosing. 

At conventional jobs, we are not autonomous because we have to follow orders from our bosses and follow company tasks.

So we should be thankful towards bbs which has provided us this opportunity to become ourselves.