CV gives practically unfettered access to renowned experts in the field in a democratic setting that would have been unthinkable in the not so distant past. Incredibly, in many cases, this is even achieved anonymously, using avatars and pen names. Personally, I try to show appreciation for this incredible gift.
On the other hand, and in the frenzy to learn and participate, it is easy to lose perspective of who is who in the real world, where texting each other would be a preposterous thought.
In this context, I wonder if it is OK to ping any user at any time within Ten Fold (as the most commonly used chat room), or if the fact that it is a chat room makes it more personal than the "open forum", and considerations such as time of the day, personal rapport with the person based on prior interactions, or status of the user being pinged in the profession should be more strongly weighted than for a regular comment at the bottom of a post.