Such things seem recurrently popular - among Christians, and also in the New Age and occult world. Those involved in group prayer/meditation/ ritual almost-invariably seem to be emotionally satisfied by their activities - yet, as so often, anyone outside of the magic circle of participants sees only a kind of self-fulfilling psychology at work.
In principle, this could be because the change is at an imperceptible spiritual level of things; or it could be that actually nothing valuable has happened - but worse; I suspect that such attempts to do good by prayer or meditation often do actual harm.
This is because people nearly always seem to be asking for the wrong things.
Either they are asking for some outcome that is inferred from distorted or false information derived from the mass media-globalist bureaucracy; or else they are asking for something abstract that itself is an evil-motivated concept...
I mean something like "peace", "justice", "healing", "safety" ;or the triumph of some particular side in some dispute.
When it comes to matters outside of our direct experience, we are on shaky ground when we engage in attempted spiritual machinations.
It is more important to pray or meditate for the discernment to know what is needed; than to try and achieve by consciously-willed spiritual-force some particular outcome; concerning situations for which our understanding is derivative and insecure (the significance of which is often externally dictated)... Situations when we personally don't really know what is happening, nor what would be a better thing to happen.
The problem is not so much that group-prayer meditation does not work as that it does actual harm - because the harm of asking for wrong things is amplified by the "group dynamics" of the situation.
There is no such thing as value neutrality. When we are not working to sustain the side of God and the good; we will very probably be lending spiritual aid to the side of evil - and/or opening our-selves to demonic influence: inviting it in.
Note added: As so often, I think this problem is a modern one. In earlier eras of human consciousness, Men were (to a much greater extent than now) spontaneously immersed in both the group consciousness, and the spirit world of the divine. But one aspect of modern consciousness is that this is no longer the case: our freedom and individuality comes with the flip-side that we don't have a natural (and largely unconscious) connection with group, angels or God. We must make a conscious personal choice to attain knowledge of The Good - and positive groupishness tends to be rare and evanescent.
