Jeff:
I’ve always been a fan / avid user of LinkedIn, but I too was bothered by the problem of unwanted invitations from people I don’t know. And I’ve always especially hated to see that practice driving people like you, Scoble, et al., away from the tool.
Well, LinkedIn just made a major change in their policies regarding invitations. Basically, “five strikes and you’re out”. When people receive an invitation, they have the ability to click on a button that says, “I don’t know the sender”. If someone gets five such hits on invitations they’ve sent, their account gets automatically suspended.
This should virtually eliminate the practice of sending invitations to people you don’t know. It will make “open linkers” have to actually contact the person, introduce themselves, and make sure they’re amenable to receiving such a request - to actually communicate (wow - what a radical concept!) - before sending the LinkedIn invitation.
More details on my blog:
http://linkedintelligence.com/linkedin-makes-it-easier-to-connect-with-people-you-know-harder-with-people-you-dont