A useful question recently appeared on SO about DI constructor injection in Scala 2.8, and I provided what I think was a useful answer. However, the question disappeared soon after I submitted my response (apparently deleted by its author?).
It seems inherently unfair that an author can unilaterally delete a question after others have answered it (unfair both to the responders and to the rest of community). It should at least require votes from other users, or there should be a built-in process that allows responders to see and vote to re-open the question.