So, either Justice Stevens is speaking on something he's totally ignorant of, (link fixed)

or he's knowingly speaking this way to give more latitude for personal disarmament laws:
Thus, the Second Amendment provides no obstacle to regulations permitting the ownership or the use of the sorts of the automatic weapons used in the tragic multiple killings in Virginia, Colorado, or Arizona in recent years.” 

Stevens criticized Congress for failing to pass such laws.
Funny, I never heard that machine pistols or submachineguns had been used in those murders.  Which is because THEY WEREN'T.  Either Stevens knows that and deliberately conflated semi-auto pistols and automatic weapons, or he doesn't know what the hell he's talking about while calling for laws to be passed.  He was a SUPREME COURT JUSTICE and says these things; ought to scare the crap out of you.

Especially his followups:
He added that the Heller decision leaves the door open to banning the carry of weapons in public. “There’s a very powerful argument for saying it does not extend to disagreeing with local communities about decisions about which public places they should not be permitted to be carried [in],” Stevens said.
He likes the idea of a federal law banning CCW.
Stevens also had a recommendation for people who keep a weapon in their homes for self-defense purposes. “Maybe you have some kind of constitutional right to have a cell phone with a pre-dialed 911 in the number at your bedside and that might provide you with a little better protection than a gun which you’re not used to using,” he said to laughter.
 Yeah, funny as hell.
 I'll note that, at the time of the Heller decision, a lot of legal people had serious criticism of Stevens' dissent; looks like retirement hasn't improved his work.

Added:
 This is a long video, but it's important to watch it so you know what the enemy's designs are, and the lawyer group announced by Jonathan Lowy is one to be on guard against. It's also critically important to understand the "legal" rationale someone like Stevens uses  to allow his fanaticism to trump his oath.  Understand reversing Heller and McDonald are just "first step" goals. Howling of paranoia notwithstanding, these traitors, who would have us believe banning handguns in the home is "common sense"  and "reasonable" and a "compelling state interest," want and intend to settle for nothing less than absolute, unchallengeable power.
And, if Romney wins, he'll need his feet held to the fire about appointment to the Supremes:
The thing to remember, with special significance to keep in mind with what we're being told about November: Stevens was a gift from the Republicans.