Actually I use it more about people... "Stop shit on them"... Also using the "You are shitting on me" as the Slavic language saying...
Which means:
doing all possible things to make another person look bad: gossips, flame, fake facts, giving only bad opinion, bulling, provoking people to disrespect the person, etc. etc. etc.
In other words:
try to put as much shit as you can to make the person smell...