Maybe a mix of anonymity and clear identity would work best. Let people have 2 profiles, one anonymous and one not, with behaviors clearly owned by the profile

Maybe a mix of anonymity and clear identity would work best. Let people have 2 profiles, one anonymous and one not, with behaviors clearly owned by the profile used. They can use the anonymous profile when they feel it might be helpful. But give people the ability to eventual discover who someone is if they have consistently bad behavior over time and when many more people share that opinion than oppose it.