LinkedIn is a professional social media that has been one of the front runners in connecting members of the business community together. It has been a vital resource for those in the professional world. In the music world it has helped connected musicians with other musicians, producers, labels, and other key players where you can see their professional background in a format very similar to a resume or CV.
Bigger social medias like LinkedIn are often targeted by hackers and crackers of the wealth of information that they have. They are also targets as one of the standards in what a secure website is. These two facts have made it where LinkedIn has strived to be one of the trend setters in what a secure site is. In this respect, their advice is not only good, but coming from a source in the cyber world that has more background in security than most other sites.