In terms of online activism, I've done my fair share before. I've avoided and boycotted products that infringe on privacy sometimes at my own detriment. The most recent example that comes to mind is switching to Android because of Apple's file scanning controversy.
But giving up GitHub would be considerably more detrimental. I'm not a notable developer and not many people rely on my code but somebody would notice if my stuff went missing. My identity as a developer would disappear and then I might lose out on collaboration and job opportunties.
Sadly, as much as I love FOSS and dislike code laundering, it's a step I can't take.