Got a call from 905 481 3057. They left a 30 second message of mostly white noise, and in the last two seconds there was a high-pitched beep and an automated voice said "goodbye". Kinda weird/creepy.
I received many calls from them and found out it is SPE - Society of Petroleum Engineers doing an Environmental Survey. The lady wouldn't give me any information about what the information was being used for, or how they got my number. She immediately apologized and "took me off their list" as soon as I mentioned I was on the National Do Not Call list.
Yikes!