I noticed that people have the ability to edit (and even completely change) their questions after answers have been received, which may make those answers no longer relevant. For example, someone posts a question, and while someone is writing up an answer to that specific question, the question's author completely changes the wording, unknown to the person who is currently writing an answer. Then when the answer is posted, it may not make sense any more because the wording of the question has changed (and consequently everyone votes the answer down because it now looks stupid and off-topic, etc).
Any ideas what, if anything, can or should be done about this? I think the ability to re-focus your questions is an excellent feature, but not necessarily if it invalidates what others have answered. After all, somebody did take the time to answer the question, why should their work be invalidated due to a change in the wording of the question?