The recommended connections algorithm is proprietary to LinkedIn, but in all likelihood it's very much like Facebook's People You May Know algorithm:
A big culprit is people who upload / sync their address books to LinkedIn, thereby compromising the privacy of all of their contacts. Another vector is friends of friends (or even several hops). Location correlations are another likely source, as are shared interests or companies that are connected. The article will give you ideas on how extensively these companies collect and mine data from myriad sources to keep pushing the creepy line, sometimes in dangerous ways.
You have no direct control over LinkedIn's algorithm, but you can take a few basic steps to reduce the data you contribute and reduce correlations:
- Do not upload / sync your Contacts to LinkedIn;
- Deny access to Location for the LinkedIn app, and don't use Wi-Fi in public places when using the LinkedIn app where you may be correlated with people you may know (your Wi-Fi Access Point or even the IP address of the AP can easily be used as a proxy for your GPS location);
- Logout and clear cookies every time you're done with LinkedIn in a browser;
- Supply LinkedIn with a unique email address that you give to no one
else ever, and give different email addresses to different circles of friends, family, colleagues, etc.; do the same with phone numbers if possible (you can easily obtain permanent or temporary VoIP and burner numbers);
- Make your social graphs private on other services like Facebook;
- Generally control the amount and type of information you provide
about yourself publicly;
- You could even seed some subtle disinformation to various sources to
These policies are vague by intention, but will give you ideas on the categories and sources of data that LinkedIn collects about you. Also review all of the settings for your LinkedIn account. You may be able to control certain aspects, but far from all. Some of these steps obviously defeat some of the purposes of LinkedIn, so each person needs to asses the risks and benefits and act accordingly.