I’ve switched over to Facebook’s comment system a while back. I did it for two reasons. First, offloading comments to a third party takes the load off my server. Second, I’m hoping to get some Facebook traffic juice.
The first part worked out. I disabled Drupal’s commenting system, which resulted in less cron jobs and queries to the database.
The second part hasn’t quite worked out. My Facebook referrals have mostly stayed the same. I’m also noticing less comments, which is a surprise. I figured since most people are on Facebook already, I would get more.
Senh: Here's an article on the legality of employers asking job applications for their login and password for their Facebook accounts. The short answer is no. It's illegal.