Every time he enters the forum he says Subhaan Allaah and the members say tasbeeh and takbeer and tahleel
Question

                We notice that in many forums, a member enters and says “subhan Allah” and in response, the second member says “Allahu Akbar” and so on, they keep doing the same every time a member enters the forum. What is the ruling on this? May Allah bless you!.
Praise be to Allah.If the one who is entering 
    the forum wants to remind his brothers to say tasbeeh and tahleel and 
    takbeer, so he says tasbeeh or takbeer and the other members respond to him, 
    and remember Allaah, then there is nothing wrong with that. It comes under 
    the heading of mentioning Allaah in a gathering, concerning which there is 
    an important, well known hadeeth: 
It was narrated that Abu 
    Hurayrah (may Allaah be pleased with him) said: The Prophet  (peace and 
    blessings of Allaah be upon him) said: “Allaah, may He be glorified and 
    exalted, says: ‘I am as My slave thinks I am, and I am with him when he 
    remembers Me. If he remembers me to himself, I remember him to Myself; if he 
    remembers Me in a gathering, I remember him in a gathering better than it; 
    if he draws near to Me a handspan, I draw near to him an arm’s length; if he 
    draws near to me an arm’s length, I draw near to him a fathom’s length; if 
    he comes to Me walking, I go to him at speed.”
Narrated by al-Bukhaari 
    (7405) and Muslim (2675).  
And he  (peace and 
    blessings of Allaah be upon him) said: “No people sit together in a 
    gathering where they do not remember Allaah or send blessings upon their 
    Prophet, but it will be a source of regret and sorrow; if He wills He will 
    punish them and if He wills He will forgive them.” Narrated by al-Tirmidhi 
    (3380) and Abu Dawood (5059); classed as saheeh by al-Albaani in Saheeh 
    al-Tirmidhi. 
The reservations in this 
    case have to do with adopting a specific number of times or order of 
    reciting, such as if he starts with tasbeeh and someone else thinks that he 
    has to follow it with takbeer and tahmeed. Believing that it is to be done 
    in a certain order, or that there is a specific number of times for reciting 
    dhikr for which there is no evidence in sharee’ah, or believing that it is 
    Sunnah to recite dhikr in this manner – all of these are bid’ahs or 
    innovations. 
The scholars pointed out 
    that singling out a time or place or specific manner for acts of worship 
    that was not narrated (in sharee’ah) is bid’ah or innovation. In that case 
    it is called bid’ah idaafiyyah (additional bid’ah) because it is prescribed 
    in principle, but is rejected because of how it is done. 
Al-Shaatibi (may Allaah 
    have mercy on him) said: Bid’ah (innovation) refers to something that is 
    newly invented in matters of religion that appears similar to that which 
    prescribed, by which people intend to go to extremes in worshipping 
    Allaah.  
This includes adhering to 
    certain ways and manners of worship, such as reciting dhikr in unison, or 
    taking the birthday of the Prophet (peace and blessings of Allaah be upon 
    him) as an Eid, and so on.  
It also includes doing 
    certain acts of worship at certain times for which there is no basis in 
    sharee’ah, such as always fasting on the fifteenth of Sha’baan (yawm al-nusf 
    min Sha’baan) and spending that night in prayer.  
End quote from 
    al-I’tisaam (1/37-39).  
See also the answer to 
    question no. 11938. 
And Allaah knows best.