US markets suffered a brief but sharp sell-off after a news agency’s hacked Twitter account claimed there had been a terrorist attack on the White House.
The bogus tweet from Associated Press’s main account told its millions of followers that President Barack Obama had been injured in an explosion.
The incident underlined the growing influence of Twitter on investor sentiment and the risks associated with inaccurate information being distributed via social media channels.
It comes weeks after the US stock market regulator gave companies permission to use social media to communicate with investors.
AP’s Twitter account, which has 1.9m followers and carries the site’s “verified” stamp of authenticity, posted at 1.07pm Eastern Time: “Breaking: Two Explosions in the White House and Barack Obama is injured.”
Within minutes, @AP’s account was suspended while other accounts associated with the news agency, such as AP reporter Sam Hananel, notified their followers that the inaccurate report was the result of a hacking attack.
The Federal Bureau of Investigation is investigating the incident. The US Secret Service said its agents were aware of the incident and “will monitor and conduct appropriate follow up”.
The momentary alarm triggered an 0.9 per cent decline in the S&P 500, wiping more than $130bn off the value of stocks. The index recovered all its losses within minutes.
“After the tweet went out, we noticed there was a liquidity gap in the market, where all the buy orders that were out there all of a sudden seemed to be getting cancelled,” said Reginald Browne, an executive at Knight Capital. “When the tweet seemed to be bogus, the market recovered.”
He said traders had discussed after the incident how the Securities and Exchange Commission might react in future amid the growing use of social media as a source of official information. Two of the SEC’s five commissioners said the agency would look into the bogus tweet.
A group calling itself the “Syrian Electronic Army”, which has targeted several other Twitter accounts in recent days, claimed responsibility for the hijacking.
Social media sites such as Twitter and Reddit faced criticism from some quarters last week, including the White House, after they played host to rumours and speculation about the hunt for the Boston marathon bombing suspects.
“In this age of instant reporting, tweets and blogs, there’s a temptation to latch on to any bit of information, sometimes to jump to conclusions,” Mr Obama said last week. “But when a tragedy like this happens, with public safety at risk and the stakes so high, it’s important we do this right.”
Mainstream media outlets such as the New York Post and CNN also played a role in amplifying the online speculation in their traditional newspaper and broadcast formats.
AP’s is just the latest in a series of Twitter hijackings, adding to pressure on the social media company to improve its security measures. Hackers claiming to be sympathisers of the Syrian government this week took control of accounts belonging to the BBC, Al Jazeera, World Cup football organisers Fifa and broadcaster CBS’s @60Minutes show.
Brands including Burger King and Jeep have also been affected in recent weeks. Some observers have suggested that such security vulnerabilities could scare advertisers away from Twitter.
Tech companies such as Apple and Microsoft have recently introduced two-factor authentication to provide extra protection to their customers.
相关新闻：
美国股市周二下午遭遇短暂但剧烈的抛售，原因是一家新闻通讯社被黑客侵入的Twitter账户发布虚假帖子称，白宫遭到恐怖主义袭击。
美联社(Associated Press)主要账户贴出的这条假消息对数百万跟随者称，巴拉克•奥巴马(Barack Obama)总统在爆炸中受伤。
这起事件是一个迹象，表明Twitter对投资者的影响力不断上升，同时也暴露了通过社交媒体渠道发布不准确信息所带来的风险。
就在几周前，美国股市监管机构刚刚允许企业利用社交媒体与投资者沟通，并允许彭博(Bloomberg)通讯社将精选的Twitter帖子纳入其面向交易员的终端。
美联社的Twitter账户拥有190万跟随者，并带有网站的“经过核实”真实性盖章。该账户在美东时间下午1时7分发帖称：“突发新闻：白宫发生两起爆炸，巴拉克•奥巴马受伤。”
几分钟内，@AP的档案就被暂停，而这家新闻通讯社的其它账户称，那篇不实报道是黑客攻击的结果。
白宫新闻发言人证实，华盛顿没有发生袭击事件。
不过，这一警报足以使道琼斯工业指数(Dow Jones Industrial Average)暴跌130点。这一股指的跌幅接近1%，但随即恢复原来的水平。