VNC is a program designed to be used for remote access. However, that cannot be achieved without your consent. (I'm assuming you mean either Real VNC or Tight VNC).
Forgive me, but your post isn't very clear on what you were trying to achieve. Quote "I started a post on networking wishing to view the desktop screen". Who's screen? Do you mean another computer within your own network, or another machine elsewhere or what?
If you were using it for someone else to access your own machine, then there certainly would be a security risk, unless you knew that person to be totally trustworthy.