https://softwareengineering.stackexchange.com/questions/1592...
https://stackoverflow.com/questions/820466/never-delete-entr...
https://serverfault.com/questions/31455/should-i-ever-delete...
https://www.infoq.com/news/2009/09/Do-Not-Delete-Data
http://udidahan.com/2009/09/01/dont-delete-just-dont/
https://stackoverflow.com/questions/2549839/are-soft-deletes...
https://azure.microsoft.com/en-us/blog/soft-delete-for-azure...
I find it fascinating how much shock there is that Facebook is doing what nearly everyone else is doing, and what many people here have likely implemented.