kag1982 asks "So who decides what is scandal? And why is a remarriage scandal? Why is not a CEO who screws over his workers subject to the same scandal?"

Under Can. 915, the minister of holy communion (ordinary or extraordinary) has the duty to withhold communion to "[t]hose who have been excommunicated or interdicted after the imposition or declaration of the penalty and others obstinately persevering in manifest grave sin."  If the minister is not aware if  any of these conditions applies to a communicant, then he or she would have no reason to withhold communion.

I would expect that if a pastor is aware of a parishioner for whom one of the conditions applies that he would advise them privately not to present themselves for communion.  An ordinary may get notify/advise clergy of persons (most likely notorious persons) to whom communion must not be given.

It is rumored that Cdl. Dolan has advised NY Gov. Cuomo not to go to communion due to his cohabitation with his girlfriend.