Got a call, picked it up and it hung up on me after 3 seconds.

just got a call from them, when I called back it was fast busy

Same as some others.  Returned the call and got a fast busy signal.

I received a call from 971-373-0141 with the caller ID of "DUMMYCOURSES" today, with no message left.

On callback, I heard the following recorded message: "Hello, and thank you for calling back. You have received a marketing call from a commercial entity or its representative. If you would prefer to not receive calls from this organization in the future, press 1 at anytime to be added to this organization's do-not-call list." Upon pressing 1, the following message is played: "Thank you. Please allow 24 hours for this removal request to be processed. Have a nice day."

We'll see if pressing 1 actually does anything or not.

BTW, the recorded message was heard on my second & third dials. I got the fast busy signal on my first callback, just as a number of the above posters did.