Good question! I would also like to know the answer. I've scanned through our sites and couldn't find any malicious content... My guess is that the block was automated, and might have been caused by a fake spam report. There can be some competition between non-profits (e.g. two scouting groups in the same local area). Maybe they started to report each other as a joke.
This is not only with printers, but with everything you search for, it makes me so sad! Everything is just full of SEO optimised nonsense. In the past it was so easy to search for something and actually find it. Now you only find crappy sites, full of ads, pop ups and brain-dead content optimised for SEO. It looks like Google has stepped away from reputation based scoring to a score that is too much focused on the textual content of sites. I hope this creates opportunities for new players in the market that are able to solve this and can outperform Google. That would be good for the internet.