Laskern, unfortunately there are “rabbis” who claim ruach hakodesh and both say and do terrible things. This is nothing new. During the time of the Bayit Rishon there were false prophets. There were Shabtai Tzvi and Yaakov Frank ar”y. There is also the infamous “rabbi from the north in Israel”. Someone once even conned a married woman into doing an extremely serious aveira by claiming to be Eliau haNavi (see Responsa Binyan Tzion of Rav Yaakov Ettlinger 154).
Shopping, the “big name rabbi” is Rav Dessler.