I had passed an initial phone screening with HR, and was scheduled for a 45-minute phone interview. Ten minutes after the phone interview was supposed to start, HR called me and told me there was a mix up, and that the manager had changed the profile on the job listing. Needless to say, I had already spent a good deal of time preparing for the interview only to get a late call telling me I no longer fit the profile. The timing could not have been worse: waiting until after my scheduled interview was supposed to start to let me know that they decided to cancel my interview was about as unprofessional as it can get.
Get a clue, Google. Don't post job listings, schedule interviews with candidates, and then go change the requirements for the job.