I am somewhat skeptical on a few related grounds. First, because any heavy handed efforts (let alone concentration camps, Jesus Christ) would quickly fill with the innocent poor. Cops are neither magicians, nor mind readers, and hence we have trials and due process. If you use those, then we already do have a means of separating gang members from society, called prisons.
Second, it requires pissing on the Constitution and its "rules," like that pesky due process and freedom of association. Again, if you can prove criminality, that's one thing, but membership in a gang is not in and of itself a crime. Also, not all "gangs" are created equal, will we round up the KKK and the Animal Liberation Front at the same time as MS-13? (The only difference between them from the semantic standpoint of "what is a gang?" is race, socio-economic status and that MS-13's crimes tend to be more drug related.) Due Process, I point out, includes notions like the punishment fitting the crime. Not all gang members are guilty of crimes of the same magnitude (not all of them are even guilty of crimes, let alone crimes that people tend to get jail time for) and you'd have to prove who did what not simply criminalize the gang as a whole and sentence them all to death or concentration camps for life.
Third, again unless you can prove criminality (preferably in a court of law), there is no difference between a "gang" and an "organization." Even if you *can* prove criminality, though the difference between a gang and groups like the Sons of Liberty (which certainly did commit crimes) is that history vindicated the latter).
This is the kind of thread that makes me happy that no one important ever reads this kind of thread.