If you're paranoid about that recent MTS exploit that was about revealing your ID, you can "change" your user ID by following these instructions (taken from http://forum.nexon.net/MapleStory/forums/thread/8206015.aspx):
What You Need to Know Before You Proceed
How To Change Your Account ID To Your Registered Email
The MapleStory team
What You Need to Know Before You Proceed
- Before you consider this option, you must have access to the email address registered to your Nexon account. This change will be permanent. If you go through with this change, you must always use your email to login on the website and game.
How To Change Your Account ID To Your Registered Email
- To change your account ID as your registered email, please submit a ticket through our Support portal under the following:
o Game Selection: MapleStory
o Category: Account Information
o Sub-category: Personal Information
o Summary: MTS issue
- Our Customer Support agents will work with each individual to address their concern.
The MapleStory team
