[nomo17k]

Many save files are now encrypted and also there's some mechanism to check the authenticity of them (via checksum I assume).... so if this is something to be serious about, I think there are ways to always identify the original roster uploader and such.

But unfortunately the anonymous nature of the internet really makes the ugly side of people come out, and there's no way to prevent that so long as they remain anonymous. There's no accountability to worry about.