How hard is it to prove online that you are who you say you are? Author Philip Roth had to publish a letter in The New Yorker to satisfy the editors of Wikipedia
Wikipedia succeeds by "not doing the things that nobody ever thought of not doing". Specifically, Wikipedia does not verify the identity or credentials of any of its editors. This would be a transcendentally difficult task for a project that is open to any participant, because verifying the identity claims of random strangers sitting at distant keyboards is time-consuming and expensive. If each user has to be vetted and validated, it's not practical to admit anyone who wants to add a few words to a Wikipedia entry.