The innovators (بدعتی) present following is the Hadeeth in Sahih Muslim to justify their inovations (بدعت):
Anas reported: A man came panting and entered the row of worshippers and said: Praise be to Allah, much praised and blessed. When the Messenger of Allah (may peace be upon him) finished the prayer he said: Who amongst you uttered these words? The people remained silent. He (the Holy Prophet again said) -: Who amongst you uttered these words? He said nothing wrong. Then a man said: I came and had a difficulty in breathing, so I uttered them. He replied: I saw twelve angels facing one another as to who will take them up (to Allah). (Sahih Muslim Book #004, Hadith #1247)
No Muslim says that uttering these words " Praise be to Allah, much praised and blessed " is biddat (بدعت). The biddat (even Shirk) is that if somebody start uttering "Ya Ghaus ul Azam" , "Ya Ali" etc.
It is very clear from Above Hadeeth that the person was uttering the words alone inside a mosque, which is still common practice in mosques.
I have personally experienced a biddat (بدعت). Some of Muslims now a days, utter words like "Allah hoo" in groups in chorus, inside a room with all lights off and at the same time shaking their head (and body) up and down. That would be called biddat.
Furthermore, during the life of Prophet Muhammad (صلی اللہ علیہ وآلہ وسلم), he (صلی اللہ علیہ وآلہ وسلم) himself was there to correct Muslims if they were going towards wrong direction. Prophet Muhammad (صلی اللہ علیہ وآلہ وسلم) has completely delivered the religion before he (صلی اللہ علیہ وآلہ وسلم) died. After his (صلی اللہ علیہ وآلہ وسلم) death there is nobody to correct if somebody is taking a wrong path, except Quraan and Sunnah.
In the end, I would like to say that, please leave this beautifull and simple religion Islam free of pollution like URS, Milad, Tazias, qawalis etc. and follow just Quraan and Sunnah because after the death of Prophet Muhammad nobody can claim that he is capable of inventing something in religion Islam which was missed by Prophet Muhammad (صلی اللہ علیہ وآلہ وسلم) (Nauzobillah).