That seems silly. I certainly don't think of archive.org as having adult content. If they do, perhaps the easy thing to do is to have archive.org and adult.archive.org that way it is easy to distinguish for people and entities that want to know/filter. Also, what is adult content to one person is nothing of consequence to the next person. So, yes I disagree with the censoring like that; glag you found a ISP that is not censoring. Also, one can use a VPN or tor; so they are not stopping one unless they also disable VPN and tor traffic.