What about other countries (Finland, Sweden, Estonia, Germany, France, Australia, New Zealand, Iceland, Singapore, China, India) or organizations (Microsoft, Google, Yahoo, Apple, Tata, Baidu, So, Pfizer)? Is there generic platform where information about IP ranges can be entered? Or are this 'one off' projects? Why not to make generic solution?

If you can identify the IP ranges you can configure anon https://github.com/edsu/anon to listen for edits from them, and announce them using a particular Twitter account.

Honestly, I just put anon together in a few hours, and didn't put a great deal of thought into it. It might make sense to do what you suggest, and create a more generic webapp to deploy on Wikimedia labs, which manages the IP ranges, and Twitter accounts to post to.