Are loud collective Duas after the Fardh Salaat Sunnah?

Answer

Loud collective duas after all Salaats are bid'ah. This practice is not restricted to the Barelwi Bid'atis. Even those who studied at Deoband and who are aware that it is bid'ah, indulge in it to please the ignorant public. When one happens to be in such Musjids where this bid'ah takes place, then it is best to stand in the last Saff to enable one to leave easily, and not be a participant in bid'ah.