Re:The top Google result for 'blockchain' is a scam ad
by sciurus on Sunday May 15, 2016 @03:43PM
(#11702393)
And when I went to view your screenshot on imgur I got an ad pretending to be an Android warning message about my storage being full in order to trick me into insuring an app. Presumably that apps true purpose is to show me even more scammy ads.
Removing it after it has been on the front page of HN is straightforward. We can't say how long it was there or how many users have been duped by this already. The case might be similar for other search terms.