If you purchased your Domain names yourself through an online registrar such as
www.godaddy.com or
www.123-reg.co.uk you'll be safe.
You may be at risk however if you let a third-party register your domains for you, such as your IT Consultant or Wed Design Company, or even in some cases your Employees. Most are honorable and respectable individuals and will use one of the aforementioned registrars to register your names and complete the process correctly by registering the domain names in your Name or that of the Company.
Unfortunately a growing number of individuals are turning to under-hand tactics by registering your domains in their name.