Ad hominem: attacking someones character instead of their argument
If the only thing you have to say in response to the claims these people are making is stupid greentext nonsense meant to derail and delegitimize discussion because you don’t like who is saying it, then you aren’t taking it seriously and just resorting to ad hominems.
Only for a very limited definition of argument, which is a logical construct that goes from premises to a conclusion.
They’re not critiquing the argument, they’re critiquing the credibility of the premises, as they require you to trust their source as they are a claim and not evidence.