It has a net negative effect because people then go around saying (this post will be deleted after policy implementation), "Oh, look, LW is encouraging people to commit suicide and donate the money to them." That is what actually happens. It is the only real significant consequence.

This is where the rubber meets the road as far as whether we really mean it when we say "that which can be destroyed by the truth, should be." If we accept this argument, then by "mere addition" of censorship rules, you eventually end up renaming SIAI "The Institute for Puppies and Unicorn Farts", and completly lying to the public about what it is you're actually about, in order to benefit PR.