What is the ruling on "charity for likes" widespread on Facebook?

The "Goodness Challenge" method is not permissible because it involves several فساد (corruptions/harms): showing off and boasting about the good deed, risking the nullification of the deed due to ostentation (riya'), it might encourage giving charity out of embarrassment rather than genuine willingness, and it might lead to admiration for what is not worthy. Legitimate competition should be for goodness without a challenge or prior collusion.