???
I'm having trouble visualizing that since a petard is a small bomb. OTOH CNN is a big bomb so maybe it works.
It’s a matter of the common use of the term in Shakespearian times. “Hoisted” in this case simply means to be forced into the air, in this case, by the explosion of one’s own bomb.
Pétard comes from the Middle French péter, to break wind, from the root pet, expulsion of intestinal gas, derived from the Latin peditus, past participle of pedere, to break wind. In modern French, a pétard is a firecracker (and it is the basis for the word for firecracker in several other European languages).
“Shakespeare’s phrase, “hoist with his own petard,” is an idiom that means “to be harmed by ... one’s own trap”, implying that one could be lifted (blown) upward by one’s own bomb, or in other words, be foiled by one’s own plan.”
He means ‘are now hoist by their own petard’.