The onus has always been on us to find the solutions. We've had to hack round Facebook comments to get them to be read, even if we had hundreds of unique contributors via the plugin. But isn't it the search engine's job to index the content?
Well finally Google has seen sense and worked out a solution, at least for comments plugins such as Facebook's. It's been a few years since most have asked for it, but now Google will read and index this content, as shown by this official post on their Webmaster Central blog.
Image from Search Engine Land.
Of course this may not be ideal for everyone. Many webmasters will have hidden content via these languages in the past to prevent Google indexing duplicated or useless content. There's now an inevitability that Google will read all this content and find all your buried secrets. Unfortunately it looks like you're going to have to come up with a new solution. They like to keep you on their toes don't they?