Pornhub is protesting this law and others by blocking the site.
Pornhub goes dark in Arkansas after age verification law kicks in::Pornhub operator MindGeek has blocked all users in Arkansas from the site after the state’s new age verification law went into effect.
My knowledge on this is very limited and I currently lack sources, but I believe the issue that Mindgeek has is not the implementation of age verification, but instead the fact that all of the work is being put on Mindgeek to implement it instead of the states. I believe they've been fine in the past implementing age verification if the system already exists and they just have to tie into it.
I'm pretty sure their main issue is that they don't want to be the ones doing the age verification. Louisiana set up a state run verification system, and pornhub has continued to operate their site in the state. I don't want porn sites to have my ID info.