Drawing the Line

Earlier today, I came across a number of comments that expressed harsh and unsympathetic attitudes towards an ordinary fellow Canadian who had concerns about proposed CPP changes and others in similar situations.
I said then that such content jeopardizes the group's existence, at least under my management. I can't be associated with such remarks.
That was followed by more sober posts and I was reassured.
However, just now I came across and quickly deleted a post that suggested physical violence against our Canadian parliament.
I realise that it was just talk, but just the same it crossed a very serious line and jeopardizes us, reclassifies this group and implicates us all by association.
That post had not been reported and had already accumulated four likes in the hour or two it was up before I saw it. That is even more concerning.
People wonder why DS disassociated herself from her Locals site. This is why. Loose cannons.
At this point, I see only these options:
1.) Regard this as a one-off indiscretion, delete it and issue a warning
2.) Delete such content on sight in future and immediately ban the offender(s)
2.) Shut down The Lions or turn over the site to someone else
Comments?