Case: An opinion is very popular in one region, and its popularity is treated without investigation as definitive consensus of the entire Muslim community.
Ijmāʿ denotes a recognized form of binding scholarly agreement, whereas custom or popularity may be a social fact. Commitment to the community upon truth does not mean declaring every widely accepted view to be consensus.
Careful reasoning distinguishes revealed evidence, a valid agreement of qualified scholars and mere acceptance by the public; disagreements still call for evidence and restraint.