I have emailed him about technical stuff. I used to treat the guy like a hero until I talked with and met him.
I once offered to create a front-end for GCC for a programming language that, at the time, was only supported by proprietary compilers. (This was back before GCC was eclipsed by clang, with its sane licensing that allows more organizations to contribute.) I got back a disjointed screed about how evil the company behind it was because not all their software was free and they were basically fascists who ate babies and if their kind wasn't defeated then the universe was doomed. (I'm paraphrasing because this was 20+ years ago, but that was the general theme.)
I've also had the displeasure of working with him more than once at conferences, and he brings the same sort of good-vs-evil delusion to even the simplest things in everyday life. He sought out opportunities to harangue volunteers about everything from lighting to the beverages available, prepped with hours of obviously practiced diatribe to "support" all his bizarre ideas. He even showed up in the middle of a conference once--the schedule for which had been finalized months earlier--and asked when he could speak, and complained about the time slot we managed to find for him and how there were speakers talking about things that weren't GPL-licensed and we shouldn't be giving them a platform to promote such evil, etc. Honestly, he's the biggest ass I've ever had to deal with at such an event.
He's an atheist, but he has way more in common with the nuttiest of religious nuts than he does with any kind of philosopher. He's right about a few things (perhaps by accident, given how many things he's wrong about), and because he happened to be right about them first, he continues to be treated with reverence and many of his ideas are given way more credence than they should be.
RMS contributed some incredibly influential and useful software back in the day, but you'd have to pay me a lot more than Andreessen is charging to read the ranting drivel he passes off as philosophy.