[ Klaus Mikaelson, Rebekah Mikaelson, Elijah Mikaelson, & Stefan Salvatore; Dean & Cas can also read/respond ]
Here's the thing. You're a family, or at least a connected group, of vampires. We're a team of hunters, and you've officially got our attention.
This is your one warning to stop everything you've been doing, and live without hurting anyone in any way, shape, or form. We can and will take down anyone or anything that poses a danger, even indirectly, to anyone in this city -- and anywhere in this world that any of us can access, for that matter. For us, at least, that's anywhere and everywhere.
I'm not going to repeat myself, or hand out second chances. Technically, this is a second chance, because the first was the chance to live and let live without anyone having to tell you, and at least one of you already blew it. That's already more chances than we usually give, and it's only because these are unusual circumstances. But if any of you are going to try to start a bloodbath in this world, then trust me, we will be the ones to finish it.
Everyone can be safe, including you-- or you endanger yourselves by endangering others. That's the way this works. Feel free to spread the word to anyone else you know who might need to hear it.