Dear Arenanet,
I have found some closed topics about this issue from 2 years ago and nothing has changed yet.
Blocked players should be blocked from seeing my online status and my whereabouts ingame.
At this time, I feel the block function is too one-sided and I desperately implore you to fix this! I want to prevent certain players from seeing me online in their friendslist. The only way to achieve that at this time, is to set my status to offline which immediately prevents me from communicating in Guild Chat. Which makes no sense, since the people I want to hide myself from are not in my guild.
Please please please please please please fix this!