Russian/rebel social media also played a role in all this, in a way that's not mentioned in this article.

There are some official and close-to-official social media accounts that are used by the Russian rebels to announce progress (Twitter, Facebook, VK) usually straight from the mouths of commanders and higher ups.

When MH-17 was downed they boasted about shooting down a Ukrainian plane only to find themselves quickly deleting all mention of it several hours later.

Those same accounts also boasted about acquiring a Buk missile launcher weeks earlier, but those status updates were also deleted.