But these items are not illegal speech (although sometimes).
These are private orgs and can legally ban whatever they want. However, phone companies are private too, but they have regulation controlling what is and is not allowed.
The issue is that banning legal speech is a slippery slope. I imagine how I would respond if YouTube banned howtos on ripping DVDs. They can legally do that and it’s based on an illegal activity.
This also opens the door for countries with restrictive laws to forbid speech about what is illegal in China, etc.