[fnordfnordfnord]

We can agree that act(s) of marital infidelity cause people to suffer. Sites such as AM are not my favorite thing, but it is simply not my place or yours to tell other people how to manage their personal lives. I do not think that the existence of AM causes anyone to think that infidelity is okay who did not previously think that was the case, therefore, AM is not contributing to the moral decay of society. I'm not going to transfer the blame to the third party. AM did not force anyone to participate. There would still be marital infidelity if AM did not exist, and as you say, I expect their contribution to be marginal.