Make all downvotes cost one karma point, and make it so downvotes are weaker - perhaps 5 or 10 downvotes needed to cancel a single upvote. This really disincentivizes downvoting, but you'll do it anyway if something is just too over the top.
The only reason I'd keep downvoting in general is for use against things like the pedophilia posts from a few months ago - if downvoting tells someone that we don't want them around, there are cases where I'm ok with that.
People already rarely downvote. (Well, except for those who do the mass downvoting.) Making the downvotes 5 times weaker, that's almost like removing them completely. Almost no one would bother.
Below is a message I just got from jackk. Some specifics have been redacted 1) so that we can discuss general policy rather than the details of this specific case 2) because presumption of innocence, just in case there happens to be an innocuous explanation to this.
So... thoughts? I have mod powers, but when I was granted them I was basically just told to use them to fight spam; there was never any discussion of any other policy, and I don't feel like I have the authority to decide on the suitable course of action without consulting the rest of the community.