content: It's not as difficult as you'd think, for the US. Tightening the borders will help. Won't solve everything but it's a start. Believe it or not, NO security is actually all that secure, you're just trying to make it less convenient to exploit. Then, simply, any time you find an illegal, whether through some other arrest, or busting a workplace, or they try and vote, anything... you either ship them home or incarcerate them for illegal presence. If that doesn't do it, ratchet up the punishments. Maybe some itinerant farm worker, you just chuck back on the other side of the wall, but someone from the cartels? show them just as much mercy as they show their victims. The end result will be that you won't stop illegal immigration, but most of the illegals who DO come here will on their best behavior. Either way, the problem stops.  I've run into the same fundamental problem banning people from a chatroom. It's too easy to get a new IP and evade the ban, but you're IMMEDIATELY EVIDENT when you do, unless you put on a whole different persona to evade my notice. And really, if I banned you for bad behavior, and you evade, but stop misbehaving, well, I've accomplished what I wanted to begin with.