Do you trust your LinkedIn connections?
LinkedIn do make a point of reminding you not to connect with people you don’t actually know and it’s worth reiterating that again in light of feature that allows you to export your LinkedIn connections.
You can export your connections list either to email or as a .csv file but either way you will obtain the email addresses of everyone on your connections list.
There are a lot of people on LinkedIn that try to obtain as many connections as possible for various reasons and you see this behaviour in all social networking sites. Mostly it’s harmless but as this is a business site the opportunities that an email address can give those of a more nefarious bent are pretty obvious and can range from general snooping to confirm where you work or harvesting the address for spam, to the more nefarious activities of trying to break into your email account or other accounts where they suspect you may have used that email address.
There’s nothing you can do to stop your contacts obtaining your email address, what you can do is make sure that the people on your contacts list are actually people you know and would trust them not to misuse the information.