All license information is in the public domain by federal law. The FCC must make this information available. There are also things like QRZ.com, the Callbook, etc., that publish your address, class of license, etc. This information is used by other amateurs to send you QSL cards and the like. The information is also available to anyone including those who are engaged in selling items to the amateur radio operator.
The same thing holds true for your driver's license, automobile license, etc. Your state is required by law to provide this information under the open records laws. The same thing is true on real property, business licenses, sales tax permits, etc.