Few days ago, I got an email alert at slightly odd hours saying: “Contact FedEx for delivery of your courier.” If it were an email, I would have immediately dismissed the message as spam but in this case, the reminder came through Google calendar.
Today, there was another reminder in Google Calendar that wanted me collect a million dollars from an ATM. Another spam and it looked like someone hacked my Google Account and thus gained access to my Google Calendar.
Fortunately, that wasn’t the case - this just an old feature in Google Calendar that allows spammers and anyone else to add event reminders to your Google Calendar without permission.
To understand the problem, create a new event in Google calendar and invite another Google Calendar user to that event by typing his email address in the “guest list” - when you do this, your event will now automatically show up in his calendar.
And this is exactly what spammers are using to pollute your Google Calendars with false alerts. They know your emails and can therefore easily insert events and meeting requests into your Google Calendar by posing as host of an event.
To prevent someone from adding events in your Google Calendar, go to Settings and select “No, only show invitations to which I have responded” under “Automatically add invitations to my calendar” section. You can also report spam in Google Calendar here.