Two firesheep denial-of-service attacks
blog.scaramanga.co.uk
blog.scaramanga.co.uk
That said, a DoS attack against firesheep users, if convicted, would probably have more repercussions than what ever identity fraud the firesheep users could be prosecuted for (per case). This is a great example of where someone trying to benefit society (preventing possible identity fraud) could be labeled a terrorist. I fear the day that the FBI starts going after "terrorists" to protect identity thieves.
I also think denial-of-service attacks against legitimate services are illegal.
But my question is, what about denial of service attacks against illegal activity such as firesheep when the attack doesn't affect any legitimate users or services? A specially crafted packet that exploits weaknesses in firesheep code doesn't harm anyone else on the network, like for instance a network flood would.
tl;dr: taking the law into your own hands is illegal, yes.
What about if I setup a device on the network that blinks a light whenever it sees that packet? I'm not trying to kill firesheep--I'm just trying to blink that light, and firesheep happens to be grabbing the packet and breaking.
I'm not just trying to be difficult; I'm genuinely interested in what would and would not constitute an illegal DoS under US Law.
Think about this: government-funded researchers in security run massive honeypots that attract hackers, who are then observed. Researchers often try to hack back through the botnet, as the Computer Security Group at UCSB did in their well-publicized ten-day takeover of the Torpig network.
Edit: Some more data:
"At the beginning of 2009, we took control of the Torpig botnet for ten days. Over this period, we observed more than 180 thousand infections and recorded more than 70 GB of data that the bots collected."
So these researchers took over the botnet and downloaded 70 GB of data that they sniffed. That's not just data on the botnet itself, but identifying data of the hosts that Torpig had infected. In this case, we have no idea what data was being siphoned around (although presumably not credentials, it's feasible that CC#'s were being moved to and from controllers). So whatever data Torpig stole, times 180,000 infections. We trust these guys because they're researchers, but are they above the law in a case such as this? Just something to think about!
If someone is already breaking the law they generally can't turn to law enforcement for protection unless the second crime is far worse than the first. Even if they do report it, practically the FBI is unlikely to show any interest - but may be inclined to arrest the firesheep user as they likely confessed directly to a federal officer.
It's unlikely that sending out a malformed TCP packet would ever be prosecuted in any case, if it would even be illegal, except for seriously extenuating circumstances.
Morally you'd certainly be in the clear as well imo.
If one guy on an unencrypted LAN is running FireSheep, and another guy is running FireFlood, I expect to see an unabated nerd fight break out.