Deaf Culture, Autistic Culture, and Language

In the wikipedia entry on people first language, this interesting bit (emphasized by me below) appears,

Person-first terminology is rejected by some disabled people, most commonly deaf and autistic people...In a reversal of the rationale for person-first terminology, these people see person-first terminology as devaluing an important part of their identity and falsely suggesting that there is, somewhere in them, a person distinct from their condition. Notably, these two conditions have extensive effects on language use, leading to significant subcultures, the deaf community and the autistic community.

While autistic people don't have a formal language like ASL, we do have some shared communication styles, shared ways we use language or other types of communication, and some shared preferences for communication styles that are different from other groups of people. In terms of community-building, someone once said to me "the Internet is to autistic people what sign language is to deaf people." (And I am always conscious of that terrible time in the U.S. when deaf people weren't allowed to use sign language, and think about current parallels to that for autistic people...)

What are the parallels between autistic culture and deaf culture? How significant is the role of the Internet in autistic culture? And what about the connection between language use and cultural identity? How does language both unite and divide?