General Keith Alexander, the Director of the NSA and Commander of the DOD's US Cyber Command, has been announced as the keynote speaker at the upcoming Black Hat USA security conference at Caesar's Palace in Las Vegas. The announcement comes on the heels of a request by Jeff Moss, organizer of the DefCon hacker conference, that federal employees take a "time-out" from attending DefCon this year because of high tensions in the wake of revelations made by former NSA contractor Edward Snowden about the NSA's widespread surveillance programs.

Black Hat occurs the same week as DefCon, just a mile away. But while the two events are both focused on computer and network security (or the lack thereof), they have totally different audiences and personalities. Black Hat is produced by UBM Tech, the media company that owns trade publications such as InformationWeek and runs the Interop technology conference. DefCon, on the other hand, is a "hacker convention," not a security convention, and tends to welcome a more anarchic demographic.

And while Moss sees the glass as half-empty in the wake of the Snowden leaks, the Black Hat conference's management sees it as half full. "We are honored to have General Alexander join us this year at Black Hat in Las Vegas for the first time," Black Hat's general manager Trey Ford told The Guardian. "We couldn't have asked for a better time to welcome him. The security and intelligence communities have common interest in protecting international critical infrastructure and the Internet at large. We both have an acute interest in defining and defending privacy."

This is a rare public speaking engagement for Alexander, who appeared for the keynote at last year's DefCon. It was that appearance that may have triggered some of the unease Moss expressed over federal agencies attending DefCon. In a response to a question at DefCon last year, Alexander said that allegations that the NSA had "millions or hundreds of millions of dossiers on people is absolutely false." That statement prompted inquiries from the Senate Intelligence Committee over whether the NSA collected data on domestic targets. On March 12, Director of National Intelligence James Clapper replied to a question from Sen. Ron Wyden on the subject during a hearing, saying that NSA did "not wittingly" collect data on US citizens. Clapper sent a letter of apology for the statement to Sen. Diane Feinstein, the chairman of the Senate Intelligence Committee, on June 21.