San Francisco: Twitter and Facebook suffered service problems from hacker attacks on Thursday, raising speculation about a coordinated campaign against the world’s most popular online social networks.
The attacks, which came a month after the White House website was targeted in a similar online assault, left millions unable to carry out daily routines that have assumed an increasingly central part of their lives.
The incidents also underscored the vulnerability of fast-growing Internet social networking sites that have been heralded as powerful new political tools to counter censorship and authoritarianism.
Twitter, which allows people to broadcast short, 140-character text messages over the Internet, became a key form of communication in Iran amid the protests and clampdown that followed the country’s disputed June elections.
A Facebook executive said Thursday’s cyber attacks were aimed at a Georgian blogger with accounts at the various affected sites, according to a report on technology news site CNET.
In a blog post earlier on Thursday, Twitter co-founder Biz Stone said the company preferred not to speculate about the motivation of the malicious attack that knocked the site offline and made it inaccessible for several hours earlier in the day.
“Twitter has been working closely with other companies and services affected by what appears to be a single, massively coordinated attack,” said Stone.
Members of Facebook, the world’s largest Internet social network with more than 250 million active users, saw delays logging in and posting to their online profiles. Like Twitter, Facebook said the problems appeared to stem from a so-called denial of service attack, a technique in which hackers overwhelm a website’s servers with communications requests.
Once access to Twitter had been restored, many of the site’s users posted short messages lamenting the disturbance.
“now I know Im addicted to Twitter...I wasnt rite all day,” Twitter user hotlilNINA posted.
Speculation swirled on the Internet that other sites, including Google, had also come under attack, after relatively lesser-known site LiveJournal said it, too, had been targeted by hackers on Thursday. But those rumors could not be confirmed.
Google said in an emailed statement that it was in contact with some non-Google sites that were impacted by Thursday’s attacks to help investigate.
“Google systems prevented substantive impact to our services,” the statement said.
Motives for denial-of-service attacks range from political to rabble-rousing to extortion, with criminal groups increasingly threatening to hobble popular websites that don’t pay demanded fees, according to security experts.
In July a wave of similar attacks disrupted access to several high-profile US and South Korean websites, including the White House site. South Korea’s spy agency said at the time that North Korea might have been behind the attacks.
Twitter’s newfound fame makes it an easy target for hackers, said Steve Gibson, the president of Internet security research firm Gibson Research Corp.
The number of worldwide unique visitors to the Twitter website reached 44.5 million in June, up 15-fold year-over- year, according to comScore data.
Security experts said a single group could have been behind the problems on Twitter, Facebook and the other sites as hackers evolve their ability to attack multiple sites at once.
“History would tell us that it’s probably the same attacker or group of attackers that is launching both attacks,” said Kevin Prince, the chief technology officer of security services provider Perimeter eSecurity.
While there are ways for websites to protect themselves from denial of service attacks, Prince said the defenses were expensive, whereas mounting an attack was a relatively simple feat for hackers.
Twitter said in a blog post later on Thursday that its site was back up, though it said certain users would experience degraded service while it recovers completely.
Some Twitter users appeared to be taking the incident in stride.
“It’s just an annoyance. Remember Twitter was down in 2007 and 2008 all the time,” said Robert Scobble, a commentator on the technology industry who boasts 93,000 “followers” on Twitter, referring to a period when Twitter’s rapid traffic growth occasionally led to several service disruptions.
For lawyer Zabi Nowald, it was just another day -- Twitter or no Twitter -- as he headed to work in downtown Los Angeles with a laptop in one hand and a Blackberry in the other.