Consider another example, if you were out drinking and someone took your keys and refused to give them back so you could drive home while intoxicated, I'd consider that morally justifiable.
Yes I understand that someone indoctrinated/obsessed with conspiracy theories can quite literally not be able to get out of that orbit without external intervention, but it’s harder to quantify and it’s harder to draw the line on where and when it’s appropriate to declare someone unfit to set their own media consumption habits.
We’d also have to clearly define what does and doesn’t contribute to the problem, which would vary from person to person. That is definitely not a straightforward delineation. Especially when the person in question doesn’t agree at all.