And we shouldn't allow this concept to go unchallenged here on Lemmy.
Commenting on an active post is not brigading
Posting a link to something is not brigading
Commenting on something you were linked to is not brigading
The only thing that might be brigading, but isn't because it isn't a real thing, is someone explicitly going, "Hey everyone, go here and harass this person"
It's all fine and good that we have some new rules to keep the peace with other instances but we must fight against 
Caveat: yes when you show someone why they're fucked up and wrong they will mentally block that out. But at the same time 100 to 1000 people will see that thread without commenting, and a lot of them will find your point convincing.
Ever post an imgur link to reddit? It has a view counter, and when your reddit thread gets like 45 upvotes and 7 comments, that's 10,000 hits to the imgur post