Chances are you have been asked this question: Do you know this person? A friend has been contacted through a social network and a connection request has been made. Your friend has determined somehow that you know the person and are thus asking you who the person is. Every social network has its nuances and rules of engagement both stated and inferred. For example Linkedin plainly defines who you should and should not send a connection request to. Right before you click send it reminds you to make sure you know the person. Now “know” can have many meanings here. On twitter, friending someone you know is pretty open. LinkedIn though has established these guidelines:
Connecting to someone on LinkedIn implies that you know them well:
They’ll have access to people you know
Others may ask you about them and vice versa
You’ll get updates on their activity
LinkedIn lets you invite colleagues, classmates, friends and business partners without entering their email addresses.However, recipients can indicate that they don’t know you. If they do, you’ll be asked to enter an email address with each future invitation.
On other networks and community sites these guidelines vary. Being familiar with the standard is both helpful and will ensure you keep as well as grow your standing within a tribe. If you don’t know someone ask a friend to introduce you. It will make a much better first impression.

As we checked into