Why are you talking about "with the same name as your WiFi"? That might change things (the people setting up the rogue network would be deliberately interfering with your network, after all), but as far as I can see that's not what anybody is doing here.
Because I'm not trying to defend what they did -- they were wrong and just trying to grab money.
I am saying that using deauth packets to prevent wifi from operating does not seem to be outright illegal and there are valid reasons to be able to do it. Considering basically every high end AP has the ability to target rogue APs and the FCC takes a dim view on people selling jammers, it seems like the context of the application of this determines whether you are jamming or not and not the use of deauth packets by itself.
Many AP's have the ability to operate outside of their proper bands and above the stated power limits too. Existence of a feature doesn't make its usage legal.
The legal principle here is remarkably clear cut.
Are you willfully interfering with another user of the band? Yes? You're breaking the law.
The method used to accomplish the interference isn't germane to the question of whether you're interfering or not.
I'm aware that nearly every enterprise AP has the ability to detect rogue access points. I am not aware of any with the ability to attack them. Also, as far as I know, none of them can target devices that are not actually attached to their network.
As someone who has experienced the fallout firsthand from a neighboring tenant in a downtown Seattle office building who used it, I'd challenge the idea that there are valid reasons to do this.
If you control the physical network - don't allow rogue APs on your network.
If you control the client and care about them connecting to access points that aren't under your control, then manage that instead.
