It can be a resume piece. Having been in these communities (server emulation instead of console) you find some insanely bright developers in them. A lot of them don't have a formal education background, but are willing to build out well thought out pieces of software. You just have to do the research on them if they tell you this is who they are, a lot of the times you can find out plenty about how they code and design things out in the open. I'd probably almost always hire such a dev if their code seemed good, and I knew they cared about the quality of their code. Having been involved in those communities though I do know there are awful devs who don't care about what anyone says "my code aint broken" types who never give credit when you help them either (reputation / respect matters more when you're coding for free in some of these communities).
I'll double down on personality that parent comment pointed out. If you see someone submit a project they worked on instead of formal education then you need to see what their exact contribution is and how they interact with other devs. Look at past github comments, issues, etc. Lurk in their chat server or pull logs. Expect to see a more casual attitude than what will show up at work, but pay attention to how contributions are handled, how credit is handled, and how disagreements are handled. It's not a universal problem, but I've seen some of the worst developer drama around volunteer open source video game projects.
Do they expect a company to believe them when they say "Yes, that anonymous social profile is actually me, John Emu maker. Really." Then if they proove it, by logging in and posting a known sentinel for example, do they expect everyone on that interview loop to keep their secret?
Companies generally don't take anonymous credentials.
This is a little too risky since it could wind up with someone revealing their identity inadvertently or otherwise. If you truly want to be anonymous you should not be leaving so many breadcrumbs. All it takes is for a former employer to have a security breach and someone to point out that they found your real identity.
