WhatsApp is experiencing server issues at this point, so the service is unavailable for all users worldwide, no matter the platform they are using.
According to a short tweet of the WhatsApp team, the service is down due to unexpected server problems, so engineers are already working to bring it back online.
At this point, it seems that users on iOS, Android, BlackBerry, and Windows Phone are all experiencing the same issues, with no message delivered to contacts for the time being.
The outage takes place only a few days after Facebook officially announced the $19 billion acquisition of WhatsApp, which makes many wonder whether the social networking service has anything to do with it.
Of course, we’re still waiting for more information on this, so we’ll update the post accordingly.
Update: WhatsApp is back online and all services should be working normally right now.