I haven't necessarily seen abuse of the down vote but I have seen some bullying on steemit this past week.
It's a group of people mercilessly harassing a man. I don't know the entire story but it still bothers me.

The downvote situation appears to be "I have a grudge against you cause you ticked me off... so this is what you get". I do not think this is fair and yes, steemit should have a monitoring dept or system to oversee such things.
If I was using steemit as an only source of income and relied upon it for survival, then these people are begrudgingly taking away my livelihood.