Meetup.com was hit by a massive denial-of-service attack after the CEO refused to pay a $300 extortion fee to unknown attackers. No personal data, including credit card information, were accessed during the five days the site has been down. The incident is the first in the site`s 12 years of operation. Meetup is a New York-based online social networking site that facilitates offline group meetings in various places around the world. It has almost 17 million members and up to 20,000 new members signing in daily.”]