A hiring manager E-mailed me to set up an initial phone interview, which he did attend. At the end of the conversation, he asked me to "do some homework" for him and research an industry topic, with plans to discuss it in depth during the next phone interview, which we scheduled for approximately a week later.
After doing extensive research on that topic and preparation for the round two interview, the hiring manager waited until 30 minutes before the phone call to cancel with a one line E-mail.
This company has no respect for your time, and no sense of professional courtesy whatsoever. Be wary when agreeing to invest your time to prepare for their phone interviews, this is how they treat people.