On Wednesday, 3 December 2014 at 23:26:42 UTC, Vladimir Panteleev
This will not help: clawling != indexing, and robots.txt only
stops crawling. robots.txt will not prevent a site from
appearing in Google search results, and it will not help in
lowering a site's search popularity. All it'll do is prevent
Google from showing snippets of Dsource pages, and indexing
links from DSource.
The existing search result ratings for DSource are because of
all the existing links to it, and not so much because of the
content on DSource.
What about using the noindex meta tag