The smaller companies may be the best bet for not training on your data, because they cannot train models themselves usually. But there is basically no way to guarantee that they wont sell your data onwards to the bigger labs. Thaura.ai has a commendable privacy policy, but that is only worth as much as your ability to audit and sue them if they fail to meet it. So effectively, its worthless. You basically have to trust them, and given so many of these AI companies start and die (or get purchased) all the time, that’s near impossible to do. If privacy is important, don’t send your data to any company.