That's like saying that the problem with home addresses is that there is no directory.
Well, that's why you ask the people you wish to interact with the contacts he prefers. Business cards, writing you a quick email, phoning them,... You know, stuff that works for centuries.
What doesn't work at all is spreading your info for anyone to see and having to spend the good part of a day to fend off cold callers.
How do I ask them how they prefer to be contacted if I can't contact them? Imagine an old friend or acquaintance or someone you briefly met at a party. A Facebook friend request is hardly intrusive or difficult to ignore.
FOAF. If you can't reach someone directly, find someone who might be able to. Through their work, friends, organizations, etc. Much of that is fairly easy to work out.
It's how people used to get by. It's called legwork.
That's like saying that the problem with home addresses is that there is no directory.
Well, that's why you ask the people you wish to interact with the contacts he prefers. Business cards, writing you a quick email, phoning them,... You know, stuff that works for centuries.
What doesn't work at all is spreading your info for anyone to see and having to spend the good part of a day to fend off cold callers.