Don't accept LinkedIn request from recruiters - ever. Reason: Your linkedin relationships/connections can help you find people you have in common - your old co

Don't accept LinkedIn request from recruiters - ever. Reason: Your linkedin relationships/connections can help you find people you have in common - your old colleague Bob can vouch for you to Mary who works for a company you'd like to work for. If you accept a recruiter, now your LinkedIn connections list is polluted with hundreds of 2nd level relationships - people you have nothing in common with except that they accepted a linkedin request from the same recruiter. You can remove these "bad" connections after the fact so its not the end of the world.