Headline is misleading, Google hasn't banned anybody, just restricting free tiers from running a particular distribution of Stable Diffusion on Colab.
I've always been amazed that Colab just hands out GPU compute for free to anybody that wants one. Obviously if you hand out free stuff that's expensive elsewhere (vast.ai charges at least 10cents/hr for a K80, colab runs for 12hrs, that's $1.2 in value to every free tier user) then they're gonna use it, so restrictions only make sense.
They're crazy powerful, if you can get something to run on them... which is especially tricky now since the free TPUs are "old" TPUs and incompatible with the framework GCS TPU instances use.
Reason: "We prioritize interactive notebook compute for free of charge tier users; the stable diffusion webUI usage got super big; we can't support the usage growth on our team's budget."
The Reddit thread seems better: https://www.reddit.com/r/StableDiffusion/comments/12t8tc7/is...
In particular, this appears to be just about the free tier.