That's the first I heard about this, but I don't really follow the space (neither Mastodon nor CSAM). Is "SecJuice" a reputable source / how legit is the report?
The one instance I have any prior awareness of, the mastodon creator saying search is not desired due to negative social dynamics, everywhere else it was presented as a privacy and anonymity behaviour - crucially, both from those who agreed and disagreed (which makes intuitive sense; on one hand I dislike e.g. Facebook not being publicly searchable some of the time, at the same time I don't want my content crawled by randos all the time either). This is the first place I've seen that frames it as explicitly CSAM related.
The author is only speculating about Mastodon's search feature, and I see no actual evidence that the search feature is intentionally limited due to child sexual abuse material.
He's right you know. Don't forget the noncery and loli culture that is going on some of the largest Mastodon instances such as pawoo.net, baraag.net, mstdn.jp.
Totally illegal explicit content in the majority of countries, only found on Mastodon.
Twitter is the only mainstream social network that is absolutely inundated with hardcore pornography. Also, Twitter has no shortage of child sexual abuse material:
On Mastodon, each instance is able to restrict other instances based on their own policies. Unless you specifically choose to join a Mastodon instance that does not restrict pornography, your instance will not synchronize content from the porn-focused instances.