I know this, we agree. I am looking for some documentation other than Ars to present to my coworkers (hell, even if it disagrees with me! I want to comply with best practices, not invent them!), and ...

Blocking it achieves nothing except to cause troubleshooting headaches. See above for troubleshooting with ping. I agree it is a valid protocol. I am not saying block all of ICMP, Im only talking ...