I've had to mature my opinion of LInkedIn over the last few ywars. When I worked at BNR I honestly felt I had found my forever home and would no longer need this tool. I wasn't intending on going job hunting. So why would I keep it if its only the source of social engineering? I've learned its a lot more than that. Its a way for me to maintain professional relationships in the same way FaceBook maintains highschool connections, college buddies, etc. I will right more on the challenges that have also matured along with my opinion when I have more time later to put down my thoughts.
I don't get this question as much as I used to but I did get it recently. Being the IT Manager at a company that has a well known public image one of the challenges we faced was attempts at phishing. No, not your typical "hey, someone stole your google password please confirm here at totallynotsuspicious.com" but very targeted to specific users within the company. I remember one instance in particular when the former owner decided to step down from being CEO, handing over the job to the former CFO. That very same day we had targeting phishing attempts pretending to be from the personal email address of our new CEO. The bad actors knew withing hours if not less of the change in leadership and saught to take advantage of it. It was then I realized that the only place that had any information about the change was the LinkedIn page of the CEO. From that moment on anytime I had a report of phishing using social engineering that depended on internal information within the company the first place I'd look to see if that information was available publicly was on LinkedIn. And sure enough. It was. I then started using my own LinkedIn as a test subject to see if they were watching my account for changes or any other useful bit of information they could find. And over time... I just left my account blank. One thing this really taught me is there are some bad actors that really pay attention to any kind of "inside" information they can get their hands on when trying to take advantage of small to medium size businesses. Small business is just the right amount of money/growth plus lax security stances that phishers love. As an IT Manager that has security on the brain most of the time I started incorporating common, and not so common but clever phishing techniques that had been usued against our company in my quartery security refreshers with all hands meetings. You'd be surprised at how many seasoned and "pro" users that sometimes let the 'what seems obvious' get the better of them. And as always... best way to fight it, is awareness and education.