Regardless of whether or not there actually is or was a terrorist cell in Lodi, CA (of all places), the FBI's use of the law should scare anyone and everyone.
Two of the men arrested are being held on charges of "lying to the FBI." Who, exactly, determined that the men were lying?
It seems that the FBI not only is playing with a stacked deck, but that they have a spare deck up their sleeve, as well. Imagine the following scenario:
The FBI shows up on your doorstep early one morning and says to you, "We think you committed Crime-X. Did you?"
You stop for a second to ponder your options. - You can say, "Yes." This ensures that the grey men will charge you with committing Crime-X, slap government issue handcuffs on you and drive you away to an undisclosed location in unobtrusive, generic sedans. The newspapers the next day will carry stories identifying a "law enforcement source" that claims you confessed to committing Crime-X. - You can say, "No." This ensures that the grey men will charge you with lying to the FBI, slap government issue handcuffs on you, and drive you away to an undisclosed location in unobtrusive, generic sedans. The newspapers the next day will carry stories announcing that you were accused of committing Crime-X by the FBI. Oh, and that you were hauled off on a charge of lying to the FBI.
Well, gollly. Those are two rosy options.
Even if you didn't commit Crime-X, and if you manage to clear your name months later after a protracted legal fight the government will never apologize for the actions of its agents.
All bets are off if you're accused of terrorism. If you're not a US citizen, you will assuredly be held as an "enemy combatant" for years without access to a lawyer or the legal system. Then, if you're determined to be innocent by some byzantine and largely random process that accepts no input from the outside world, you'll be quietly released and a one paragraph notice may appear in a few of the larger papers around the nation.
If you're a US citizen, the government may first attempt to revoke your citizenship so that it can hold you as an "enemy combatant" (see above).
So yeah, it's a good idea to let the FBI run around arresting people on charges of "lying to the FBI." That doesn't seem like a law ripe for abuse or anything.