[dragonwriter]

> So? So is calling people "rapists" (without proof or conviction), but we don't outlaw it.

Falsely calling someone a rapist is unlawful and subjects the person doing it to legal consequences many places (including most jurisdictions in the US); where the burden of proof is on demonstrating the truth or falsity of the statement, whether and in what circumstances a good-faith mistake of fact will excuse the offense, etc., vary from jurisdiction to jurisdiction, but it is certainly not a matter on which it is some widely accepted principal that people are free to make false claims without consequence.

[tomp]

Hm... plenty of men have been publicly accused of rape by women (Duke lacrosse case, the Mattress Girl, Rolling Stone "Rape on Campus", to list a few). I don't recall any legal repercussions for those women. I'm guessing that's because it's really hard to prove they're lying (even though in many cases there is very obvious evidence that they were), but this fact doesn't really support your claim that calling someone a rapist ever results in legal consequences (let alone criminal consequences).

[dragonwriter]

For one rather well-known case of non-criminal legal consequences: https://en.m.wikipedia.org/wiki/Tawana_Brawley_rape_allegati...

Discussion of criminal recourse (and considerations involved in pursuing it, from prosecutors' perspective) is here (starting on p. 8): http://www.ndaa.org/pdf/the_voice_vol_3_no_1_2009.pdf