UPDATE: Upon further reflection, it strikes me that this is dangerously close to fraud. It's not financial fraud, since people don't pay to use basic twitter, but it's fraud in that people are being enticed to interact with twitter and spend time on the site. The return people expect for that is attention to the content they produce. If twitter has instead shadowbanned you, you're still interacting with their site since you don't know any better. But no one can see your content, so you're not getting your part of the deal.