Yes, perhaps I am slow on the uptake, but have there been credible specific threats?
There have been several articles, the first one was a long time ago, Canada Free Press which is an excellent site.
If by “credible” you mean “those threatened stated publicly how they had been threatened and by whom”, no.
But if you can find the first CFP article, you will see that media people spoke to or communicated via email (I think there were phone calls too) with the author of the article about threats.
Also after Lou Dobbs brought up 0mugabe’s eligiliby shots were fired into his house, and then he was fired. And the day after Breitbart was killed, Limbaugh received some kind of weird “plaque” commemorating Lincoln’s assassination.
Just a few little things like that. There may be more evidence. But you should really try to find that first CFP article.