WhatsApp took to Twitter to complain about the problems with the instant messaging service, while others joked that the app's recent multi-billion dollar deal with Facebook was behind the two-hour outage.
WhatsApp undergoes some downtime, as founders are too busy counting out their Facebook billions one bill at a time
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The 100 leaders did not agree on concrete proposals, but the meeting has raised hopes for concrete international agreement next December.
The speech was OK, passionate at times and certainly well received, but did not display the passion of past speeches.
The brother-in-law of a British hostage being held by Islamic State militants in Syria, says he is scared by US airstrikes in the country.