I received the following e-mail October 29, 2007:

Seriously, I'm still stunned that someone would seriously threaten me over using a normal English phrase that I have used for years and that ANY English speaker should use more often.
Parenting Peacefully (formerly known as Peaceful Parenting)

Note in 2024:
I didn't expect that site to last, but what's there now is a blog with a couple of things by people other than not original site owner. PeacefulParenting.com

Dr. Buck has moved to another site, but maintains the registered trademark. Here's the newer page.