Have they ever done that? I wasn’t aware of any such thing.
https://news.ycombinator.com/item?id=9966118
https://github.com/nixxquality/WebMConverter/commit/c1ac0baa...
Here more about GitHub suffering from state-censorship: https://en.wikipedia.org/wiki/Censorship_of_GitHub
GitHub also censors any content that they deem stolen (such as the NSA Malware / EquationGroup releases) and content that they deem containing PII-data (such as the public LinkedIn crawl of people stating they work for ICE).
GitHub makes judgment calls on what to censor: They deem a project name offensive, they deem some piece of code stolen (unless the NSA admitted to them it was legit, they had no confirmation), they deem publicly available data crawled from the web PII or harassment instigation.
Unless you do not classify these examples as censorship, it is what it is.
The objection stems from the fact that censorship is always a dominant issue raised in discussions about platforms for sharing and, while it's important to keep it in mind if you're the type of person who might share controversial or objectionable content, that is type of sharing is the minority.
If we were in an oppressive regime like China where state mandated censorship is the norm, then it would be a much more pressing concern. But for most of us, we're not under an oppressive regime and decrying the platform for censorship is on par with complaining that reddit won't let you dox people or flicker banned you for posting kiddieporn.
Sourceforge did some absolutely egregious things, including bundling adware with windows binaries.
Maybe the people at Microsoft don't know it, but one of the reasons GitHub has such a huge market share is because it hasn't done any of those things.
Sure, MS could have bought it to use its reputation as capital and try and maximise income at all costs. It seems that would be somewhat counterproductive, given the long process Microsoft has gone through to start fixing its image with developers.
Microsoft would only stand to gain (short or long term) if it's been engaging in its traditional EEE strategy this whole time and is ready to pull the trigger on that final E. Even if that's the case, I can't see any real benefit; it'd just be a middle finger to developers.