Often better than the passive voice is simply "They say" or "They did," without saying who "they" are.

If "they" is too obviously a weasel, use "people" or "many people" or some similarly opaque variant.

The benefit is that "they" and "people" emphasize human agency, making the claim more vivid, while the passive doesn't. What's more, it's easier to mislead with "they" and "people," since the passive voice at least declares clearly what was done, but "they" and "people" give no clue as to whom is referred to (maybe nobody).