Comment by marbu

One way would be to run such tool before posting and then based on the results, tweak the post and repeat until the similarities are not statistically significant. Or instead of tweaking, start posting under a new throwaway account. But this won't save you when some new way to analyze style appears in the future. Moreover there are other types of meta data which can be taken into account to narrow down the search space a bit such as timestamps. And obviously more you write, harder it is to control these things.