I think csam is a direct object, with the subject being filters.
Discussion
What?! 😃 Human speech, Sir, not coding now.
Filters on coffee against csam = good
Filters in chicken soup against csam = bad
...is the equivalent. The focus is on the on the double standarts.
I'm not talking about code. I'm referring to parts of English (human or otherwise) usage.
https://www.perfect-english-grammar.com/subjects-and-objects.html
Alright, I'm no native speaker, so instead of subject I clarify my statement and modify the term to: topic.
The topic is csam.
To be most precise: the pro-filters argument for both networks is the fight against the spread of csam.
They’re putting csam in coffee now?!? Bastards!