Spam and Privacy

Yes.
But if you would like to keep someone from knowing if you are online/offline, you can simply add that person to your Invisible List.

Follow these steps in order to do this:

1. Click Menu > My tools > Settings.
   
   
2. In the Settings window, click Privacy from the Advanced list on the left.
   LI>Click Manage Block and Invisible Lists, and click the Invisible tab.
   
   

3. Move the person you want to add to your Invisible list to the Always Invisible list.