WhatsApp, a popular messaging app, suffered a massive outrage for more than three hours on Saturday.
The technical glitch comes just days after Facebook bought the mobile messaging service for a jaw dropping USD$19 billion.
WhatsApp posted a message via its Twitter account that the site was experiencing server issues and they were working to fix it.
The tweet said "Sorry we currently experiencing server issues. we hope to be back up and recovered shortly."
WhatsApp did not say how long the outage lasted, but about 2.5 hours later it tweeted again to say: "WhatsApp service has been restored. We are sorry for the downtime..."
Reportedly, some users made hue and cry by posting their anger, on social networking sites, particularly, Twitter.
The hashtag #Whatsappdown was trending while users were urging Whatsapp to turn down Facebook's offer.
The specialist website techcrunch.com suggested the problem might be down to "a surge of signups and usage that has overloaded its servers" after the publicity the app garnered following Facebook's announcement on Wednesday.
WhatsApp, a startup founded in 2009 by Jan Koum and Brian Acton, two former Yahoo! employees, and has since grown to 450 million users.
Recently, Social networking giant Facebook acquired whatsApp, a fast growing messenger app with 450 million subscribers, for a whooping $19 billion in cash and stock.
In order to gain a strong hold in the emerging markets, where Facebook's own messenger failed to click with users, the deal could be seen as a last big catch to expand fading social networking empire.