You’ve been here before: You’re at work, you get a notification via a popup, then an email, then a text reminding you of an appointment on your calendar. For most busy professionals, this is pretty normal because you know you need multiple points of contact to remind you of your schedule so you don’t look like a fool and miss an appointment. Online calendars rock, and they beat the heck out of paper calendars.
http://robertsiciliano.com/blog/2013/10/28/scammers-use-online-calendars-to-phish-victims/