My friend is called for a job interviewing at Starbucks a few days ago. IMHO, but these kind of places a not very suitable environment for interviewing specialy for programmers. Actually, my question has 2 sides;

Side of Interviewers: If you are interviewing at starbucks with a candidate as an Interviewer, How candidate should act there you prefer? What he/she should do or not? What would you pay attention on his/her?

Side of Candidate: How you should act instead of interviewing in a meeting room? Should you drink something or not (if Interviewer ask)? Should you ask a question like "Why am I interviewing in this place?"

What is the advantages and disadvantages of an interviewing by programmers in this kind of places?