Males get their Y-DNA from their father and both males and females get their mtDNA from their mother. Because surnames generally follow the Y-DNA, groups of individuals with the same Y-DNA can find each other thru surname societies. Is there an equivalent to a surname society for people who share mtDNA? Ie are there any societies arranged around matrilineal lines instead of surnames?
At the familytreedna site there is a description of Project Katrine.
If there was one society for each haplogroup, it might be too large to be useful for finding cousins.
Also few people would be able to trace their matrilineal line back far enough . Pople who took Randy's Saturday Night Fun challenge seemed to hit a brickwall fairly quickly.