It's always a good thing to be aware. There are real dangers out there faced by LEOs every day. That said, the article is a little over-the-top. The author refers to the FiveSeven loaded with SS190 ammo, which is not only armor-piercing, but also restricted to law enforcement and military only. No civilian can get their hands on it...FN won't even sell it to individual officers, only to departments on letterhead.
The civilian-legal ammo is SS192 hollowpoint ammmo, which lacks the steel core of the SS190 and is classified as non-AP ammo by the BATFE. It will still go through a level II vest, but only by virtue of its small size and high velocity, and much in the same way that any small HV pistol round will go through kevlar...like .22 Magnum, or 7.62x25, both of which have been available for decades.
I wouldn't be too concerned about the Five-SeveN. Those things are very expensive and rarer than hen's teeth, the civilian ammo is expensive and hard to find, and the unrestricted loads won't do anything that a .22 Magnum out of an AutoMag II won't do for a lot less money.
Now I am actually pondering selling my brand new Five-SeveN. It would make a swell little carry gun, as it is very lightweight and holds twenty rounds, but I'd rather not get pulled over by an officer who has that bulletin in the back of his head when he discovers that I have one of those things in my holster.
(Then again, he may just be a fellow gun guy, and ask to take a look at it.)