Firstly, I usually don't have the methods being asked for. I don't use Linked-In, I barely use FB and certainly can't remember my password. And seriously, would you go around giving your phone number, email, physical address, etc., to everyone? The opportunities for social engineering abound.
And just because the people I give it to may be trusted today, there's always (a) buyouts, (b) security breaches, (c) going rogue.
Why are you asking these questions? Are you trying to learn about security? Are you surprised at the responses?
Would you, without reservation, give random people your email, phone number, login-id for other services, etc?
If so, why do you not have concerns?
