The phrase "cruel hoax" refers to a dishonest trick or deception that intentionally causes harm, often by playing with someone's feelings or expectations. Full definition
One group of archaeologists, led by Anthony Harding, president of the European Association of Archaeologists and a professor at the University of Exeter, wrote an open letter to the Bosnian government denouncing the pyramids as a «cruel hoax on an unsuspecting public.» (discovermagazine.com)
It's a very cruel hoax at a time self published writers are working so hard to make themselves look professional. (accrispin.blogspot.ru)
Morally, then, we can no longer ignore the troublesome issues about the redistribution of wealth; plans for improvement without accompanying demands for social and political reform are a cruel hoax. (religion-online.org)