Yandex, Russia’s largest search engine, has announced (in Russian) that they, as a test, are crawling through CSS and JavaScript files. The reason behind this is so that the search engine will better understand web pages and the content on those web pages that have been designed with more modern browsers in mind. Right now, there is only a small subset of known pages that Yandex is crawling, but they are planning to expand the amount of pages that are being crawled in the future.
Since Yandex is trying to crawl these new bits of the internet, webmasters are being asked that their CSS and JavaScript files aren’t blocking the Yandex crawler.
This information has been summarized in the Russian search blog in English. They also said that, “this change in Yandex’s indexing routines can possibly have effects on Yandex SEO, at least in the long run.”