A recent survey asks recruiters what is the #1 way to get on a company's radar on Facebook? 86% say to "like" them on their company page.
If you've never checked out the company pages on Facebook, now's the time. Some companies have a robust, built-out presence - others have almost nothing. But if companies you are targeting are active on Facebook at all, you have a golden opportunity to interact with them there. You can comment on the company's news, keep tabs on what they are doing, and "like" even specific comments.
It sounds as though recruiters are monitoring the activity - and it would benefit the job seeker who is part of it.