Whenever you are registering a new domain name or if you open one of your domain control panel of yours' you may notice privacy protection area. Here you can enable it or disable it. With some domain register they will charge extra US$ 10 more with the domain price. While it is free when you register your domain name with domainkade.com
Well, if you didn't enable your privacy protection who ever check the whois report of your domain name will get your entire personal name, address, phone and email address. This information will open path for you to get spam mail and open path for domain theft and fraud actions against you.
It is compulsory law that you must provide your true personal information along with the contact address, email and phone number, when purchasing (Registering) a domain name from a register.
So if you had enabled the privacy protection, it will secure your personal information by removing it from the publicly available Whois database. The register will provide their secondary company contact details there and if any one wants to contact you then it will be diverted by the secondary company to your true contact addresses.
This privacy protection faculty will not be available for all the TLD domains. The facility is available for .com TLD domain for sure.
Any person with the correct knowledge of the internet can find out the true information of the Whois data of a .com domain name owner, but with many difficulties.
This privacy protection is only to assist you and will not allow you to violate any law of the land as it will pave path to termination of domain service.