A Discussion about HDCP

As an AV installer, I've begun to notice that certain source/display combinations simply do not work due to HDCP.

I've seen this around, but never paid it much attention (mistakenly) until recently. Now I have just a couple simple questions for my friends here in the forums regarding this technology.

1) Is this some sort of standard or DRM? In regards to HDCP, I've also encountered DDC ?encryption? that some HDMI 1.3 & 1.4 cables, certain set-top boxes, and some older monitors/TVs that do not comply.

2) Any protips for troubleshooting/working around/retrofitting an HT stack that is encountering HDCP errors?

3) The most frequent encounters with this error seem to result from the use of a particular dual Cat5e HDMI balun that I use, that appears not to have a proper channel for DDC HDCP. Are there any particular brands of balun out there that are pretty much guaranteed to work with this protection? If so, I'd like to have my warehouse get in touch with their supplier.

Any additional info would be appreciated. And before anybody asks, I am NOT referring to DHCP for networking, but High-Bandwidth Digital Copy Protection, or HDCP. Thank you all in advance.