>>> I've got too many members from all around the world, to manually approve each and every one who wants to join, and many barely speak my language.
Allowing folks to join but keeping them moderated is still unsafe because you are letting them enter inside your house unchecked.
>>> But I'll gladly restrict them from posting until I know they are real.
Yeah, but they are already inside, and while they may not post, they can still receive email/harvest addresses or do other crap they shouldn't be doing, all day long, and there is nothing you can do about it because you are enabling/facilitating it. If that rush of AOL address was a single one instead, you's have made nothing of it and wouldn't have reported it, and it would stay there NMM for years, quietly doing its thing.
Manual member approval (Restricted Membership checked) stops them at the door, and the only way they can come in if you let them.