Congregational
    Takbeer in the mosque when hearing good news
Question

                Is it a bid'ah to yell "takbeer"
    or "tasbeeh" everytime you have som good news in a masjid so that the
    congregation can chant in a group?
Praise be to Allah.When the Prophet 
 (peace and blessings of Allaah be upon
    him) heard something that pleased him, he would say: Allaahu akbar, Allaahumma la
    aysha ila aysh al-aakhirah (Allaah is most great, O Allaah, there is no
    real life except the life of the Hereafter). (Narrated by Ahmad). So it is permissible for a man to say Allaahu akbar when he sees
    something that makes him glad, and he can raise his voice, without going to extremes. But
    congergational Takbeer, where everyone starts and ends at the same time, is not prescribed
    in Islam, because there is no report to indicate that. But if one person says Takbeer,
    then another and another joins in, and they happen to say it at the same time, without
    prior agreement, then there is nothing wrong with this. They can also prostrate (sajdat
    al-shukr  the prostration of thanksgiving) if it is a serious matter. And Allaah is
    the Source of help.