Since the mid-seventies recession has followed recession to the point that everybody will experience a number of economic cycles during their career. One of the constant principles of thriving in such a situation is the principal of Maintaining Weak Ties; which means checking in with previous colleagues and contacts regularly. Eric Granovetter discovered in 1977 that job seekers who maintained larger networks got placed in jobs more quickly than those who ignored all but the most immediate contacts.
In practice this means calling on people personally in preference to using Social Media. It’s not a question of one or the other, personal is best.
Try networking using the PIE method (Asking about the work that people do to find their skill set and knowledge base) and see what happens. Here’s the technique in action.