HTC today responded to concerns about the future of custom ROMs after a site that was hosting ROM Update Utility files -- HTC's proprietary full restore files -- received a takedown letter from a lawyer representing the manufacture. The site -- -- posted the apparent exchange at Reddit (and was later picked up by Rootzwiki). HTC on its blog today explains that it was the branding -- the use of the HTC logo along with the domain name -- that was really at issue. 

Wrote HTC:

The issue with the site in question was NOT that it provided custom ROMs or RUUs. The site used HTC trademarks without a license from HTC. The domain name contained ‘HTC’ and it used HTC logos, making it appear to be an official HTC website. Like any other company, we must protect our trademarks and brand. We cannot risk being associated with, and held liable for, software that we don’t have any control over that’s put onto an HTC device through a third party.

Stockpiling RUUs remains a bit of a gray area -- we've seen other sites taken down over the years -- but HTC pointed to its bootloader unlocking problem (which remains subject to the whim of its clients -- the carriers) as proof that it's committed to the modding community that that "we think the custom ROM community is valuable to the overall health of the Android ecosystem, and we have no intention of abandoning them."

Source: HTC