Is it obligatory to denounce someone who supplicates aloud and in congregation after the prescribed prayers, taking into account the difficulty some of them have in accepting advice, and what is the best way to denounce it?

Enjoining good and forbidding evil is one of the greatest rites of the religion, and there is consensus on it. It is a communal obligation (fard kifaya); if a sufficient number of people perform it, it is lifted from the rest. If no one performs it, it becomes obligatory upon everyone. The disobedient person who neglects it is exposed to Allah's punishment. It is stipulated that the one who enjoins good and forbids evil must be knowledgeable (faqih), gentle, forbearing, and aware of what he is enjoining and what he is forbidding. As for the common person, he must enjoin what is clearly good and forbid what is clearly evil. Regarding evils whose ruling is ambiguous, he may convey the fatwas of the scholars concerning them with gentleness and kindness.