I won't link to one as that's highly questionable, but there are account creation programs designed to bypass SMS verification.
You can look for them on your own if you care so much for them. My goal isn't to stop hackers completely.
My goal is to slow them down without hurting legit players. SMS verification isn't very secure. Plenty of players don't want Nexon having their information, either.
I've said in the past that phone verification would work to some degree, but that I oppose it.
Today there are fake programs. such as phone, email, voice recognition, SMS via Google Play Store programs and other websites, this is the problem, many hackers will use these methods to continue in the game and legitimate players who have 2 or 3 optional accounts would be affected, adding this would be a catastrophe because simply nexon is not prepared for this, maplestory .. no .. nexon .. practically became ubisoft and others like Activision, Depp silver and gearbox and other companies for disaster in their games help their communities etc etc
I don't know what you think you have in mind, but you may want to check your math there, sport.
There are tools that can do that, yes. Just look on github. Really people, it's not nearly as air tight as you think.
The number of banned accounts thing would be what really kills it. You run into the problem of every phone number under the sun being blocked from Nexon accounts though.
Remember that Korean MMOs are backed by real world data as well (KSSN) and they still have hackers.
It might slow them down, but it certainly won't stop them.