They're so advanced in technical skill they didn't think to turn off the feature that tells the user you're snooping on their profile? I use LinkedIn to validate user information and I turned this off immediately.
Note it was the lawyer who went to their Linkedin pages not the P.I. who they hired for technical skill. You can't always save your clients from messing things up.
Unless the lawyer wanted them to know he was looking. Might make some of the developers nervous.
In which case, it might be the case that the lawyer just clicked on thousands of developers hoping to hit the right ones and scare them in to stopping their work on Popcorn Time or doing something to make themselves known.
It may have been intentional, to frighten them. If that was the case, it seemed to have the desired effect.
They might have hacked other websites and maybe didn't find any vulnerabilities for linkedin.
I didn't know this was a feature. I just googled it and the common thread in search results is the fact that most people didn't know this feature existed. I guess I am (and most people are) unadvanced in my technical skills because I didn't know about this.