What's unfortunate is that it's not controversial. It seems Clapper has the backing of a pretty big group in Congress.
That is absolutely, 100% not the case. Dodging the question, for this particular question is as much a leak of classified information as giving up the answer directly.
This is by the same principle used by hacktivists called the "warrant canary", which they think they invented: But the same thing happened to a CIA director (Helms?) in the 1970s and he did the same thing because the same principle applied back then too.
You can read the letter: http://www.lawfareblog.com/wp-content/uploads/2013/07/2013-0...
There were ways to answer the question without jeopardizing a classified program. It has been done before and will be done again.