http://www.cnn.com/2006/WORLD/europe/02/20/austria.irving.trial.ap/index.ht…
Looks like you don't need to go to the extent of causing death or injury.
ObDisclaimer: I'm not sympathising or otherwise supporting Irving's
views. But I'd be curious to know exactly what he's being charged
with, and what the rules on free speech are in Austria...
Steve