How can I block someone so they can not see me or see when I'm online?

[WillGrayton]

How can I block someone so they can not see me or see when I'm online? Thank you.

[Syo Emerald]

You can not really do that. Blocking only prevents them from interacting with you. They will still see you, when you are both at the same place. And they will be able to see, if you are online. You can change your settings that only friends can see if you are online, but it might be still possible for the person to see you online if you are both in the same groups.

[WillGrayton]

Thank you so much Syo Emerald

[Lindal Kidd]

I will add to Syo's answer:

Because there is always a way for someone to find out if you are on line, Blocking them is the best alternative.  If they show up, they will appear only as a nametag (or a green cloud, or a gray silhouette, depending on your viewer and settings.)  You won't hear chat or voice or sounds or IMs from them, they cannot send you objects.

It's a sort of nasty, warm, guilty pleasure for me to see some jerk I've Blocked hanging around uselessly and knowing how helpless they feel to be on the outside of my Second Life, looking in while I have fun without them.  A definite "nyah, nyah" moment.