The fifth pillar is owning everything anonymously.

Bitcoin was intended to be an anonymous currency, almost more of a proof of concept than anything else...

@Andrea DiPernaI am answering taking into consideration most of the other comments.Bitcoin is not anonymous.

At the bottom of my ad I ask questions that folks must answer when they respond by anonymous CL e-mail to get an answer back from me: How many people?

Yes, you can "legally" do it.Benefits are asset protection, liability limitations, professional appearance, anonymity, etc.Requires some upfront costs, warranty deed to transfer if already owned.

I give generously but anonymously.

There's been a vitriol snowball on this thread, as is the tendency when outrage collides with instant gratification and the relative anonymity of the internet. 

Is there any advantage (or disadvantage) to addressing that fact in the letter or is it better to send the letter as an anonymous investor who happens to be a neighbor?

Maybe I'm off base, but I always feel kinda bad for a seller who thinks that calling the number on an anonymous sign in a vacant lot next to the Dairy Queen or responding to a "handwritten" yellow letter is a good idea.

The purpose of trusts, in broad use, is anonymity.