I'll see your Gary Thomas Rowe and Vicki Weaver, and raise you a J.Edgar Hoover.
Why is it strange that criminal types are under law enforcement scrutiny?
But in all seriousness, here’s a more complex and possibility even more infuriating example: two of the 9/11 hijackers - Nawaf al-Hazmi and Khalid al-Midhar - lived in a San Diego apartment in 2000 due to the generous assistance of a possible/probable Saudi intelligence officer (Omar al-Bayoumi, who himself was apparently receiving direct or indirect financial assistance from Saudi Ambassador Prince Bandar and his wife, as was at least one other associate - Osama Basnan, who was openly known to be a big fan of another, more famous Osama...).
These were, of course, the same two hijackers that the CIA failed to tell the FBI about for a very long time. The twist? One of Hazmi and Midhar’s roommates in that San Diego apartment was an FBI informant.
Not unsettling in the slightest...
Until you can actually prove the person has done something is more the issue...unless they're the wrong color and you're scared, in which case arrest is the least of that person's problems.
It's the "pretty much" qualifier to concern ourselves with when talking about organized crime. They have lawyers - good ones even - which makes arresting them without evidence a more dicey proposition that can result in lawsuits. Arresting and charging someone means that law enforcement has to present their evidence, and if that evidence is insufficient then it could mean compromising the means by which the evidence was gathered - burned witnesses, bugs, phone taps, etc.
Is anything that I stated false?