As far as deletions not working, I used to work in Public Health and disease intervention was a big thing. Someone had a communicable disease, and we got involved to prevent the spread. You likely would have said we were ineffective, since we still had cases of the disease. We couldn't have proved you wrong, since there was no way to know what was prevented, and therefore, didn't happen.

We are not talking here about measures to prevent disease from spreading. If we were the focus would be on encouraging folk (mainly by example) not to respond. And that is a positive measure I fully support and have encouraged for many years.

The measure of deleting contributions only after they appear, have done their 'damage' and been brought to our volunteer's attention for subsequent deletion can not be considered as a measure to prevent anything. It is prbably more akin to surgery. Which is sometimes used to prevent the spread of a disease or infection in an idividual case - but on its own, does litte to generally prevent the disease itself.