More than 500 million people are using Messenger each month, says the social networking giant. Messenger is Facebook’s instant messaging app, which was also the company’s first standalone app launched in 2011. The company made it mandatory for users to download Messenger to send and receive messages on Facebook, in July this year. Facebook also owns messaging apps WhatsApp,which the company acquired in February this year.

Facebook was down Wednesday afternoon, generating an ‘unable to connect to the Internet error message’, when users tried to access the site. The outage lasted less than an hour, and users around the globe may have been affected.