It works because apperntly the people who code l2walker have there own auth server in there local area network and thus for testing reasons have made it so that when it connects to a local (free ) network it automatically authenticates. . .
Its like if you wrote a program and wanted to test it quick you write a quick way to auth it. . .
As for the american login working for Europe
w/e works right?
Ps: for those who are new 2 l2 walker heres a few tips on not getting caught
Set up more human like settings
(pick up only stuff you need etc)
(don't leave tons of adena on the floor)
(don't bot in populated areas)
(Don't use automated response feature)
(don't afk bot for 8 Hours++)
(set up sound alerts so that you can hear when some 1 is near you or talking to your char)