Or, a less drastic approach is still be on Linked In and now know they are a bunch of arsehats who aren't to be trusted with your personal data so make sure you delete everything that doesn't directly give you value.
You then move them way down in your list of admired companies and actively badmouth them whenever it's appropriate - with the long term goal that this information will spread, hopefully ruining the value of being on the network to the point where it is no longer a useful resource and THEN delete your profile.
Actually, I think LinkedIn is a very interesting case for this kind of behaviour. I have long since removed a lot of personal information from my Facebook account because everyone on there is already my friend, and anyone who wants my phone number can just ask me for it.
However, LinkedIn contains a great deal of discovery and connection with people you don't know- if you removed your work history etc. then the site isn't going to be as much use to you. It isn't anywhere near as easy.
You then move them way down in your list of admired companies and actively badmouth them whenever it's appropriate - with the long term goal that this information will spread, hopefully ruining the value of being on the network to the point where it is no longer a useful resource and THEN delete your profile.
That's what I'm going to do.