Likewise, got the same threatening pop-ups, which spooked me more than somewhat.
And no I didn't re-instal an adblocker after my recent crash because there were so many things hanging around that speed was beginning to be affected... and I do take the point that the advertisers are helping to finance this site.
But *Mods* can you advise one of the IB boys and girls please, asking them to find out who is doing this scam?