"None of these “ISIS arrests” involved any actual members of ISIS, only members of the FBI... posing as such."

Propaganda and fear mongering.  Zero for 40 at Predicting Attacks: Why Do Media Still Take FBI Terror Warnings Seriously? — FAIR:

"The ominous FBI (or Department of Homeland Security) “terror warning” has become such a staple of the on-going, seemingly endless “war on terror” (d/b/a war on ISIS), we hardly even notice it anymore. Marked by a feedback loop of extremist propaganda, unverifiable claims about “online chatter” and fuzzy pronouncements issued by a neverending string of faceless Muslim bad guys, and given PR cover by FBI-contrived “terror plots,” the specter of the impending “attack” is part of a broader white noise of fear that never went away after 9/11. Indeed, the verbiage employed by the FBI in this latest warning —“we’re asking people to remain vigilant”—implies no actual change of the status quo, just an hysterical nudge to not let down our collective guard. There’s only one problem: These warnings never actually come to fruition. Not rarely, or almost never, but—by all accounts—never. No attacks, no arrests, no suspects at large."