You probably aren't familiar with the name Ata Hakcil. He's a computer engineering student who recently conducted one of the largest password security surveys currently available.
To conduct his research, he collected a number of username and password "data dumps" from the Dark Web and analyzed the passwords he found there. Hakcil was able to analyze a massive collection of more than a billion passwords, looking for trends and commonalities.
IT Security Professionals have long known that password security is an area of persistent weakness that leaves companies of all shapes and sizes exposed. Hakcil was able to measure and assess just how bad that problem is. What he found was depressing.