(CNN) -- Misinformation can spread quickly on Twitter, each retweet exposing it to wider audiences and even resulting in real world impacts.
On Tuesday, hackers took over the Associated Press Twitter account and falsely claimed that there had been explosions at the White House and that the president was hurt. The tweet was up for a few minutes and retweeted more than 3,000 times before Twitter took the account offline.
The AP immediately confirmed the news was not true, but the tweet was up long enough to send a shudder through the stock market, which plunged 143 points before recovering.
Real tweets have the power to end careers, cause diplomatic tensions, fuel a revolution and find a kidney. Fake tweets can have the same ripple effects, and damage control is difficult. There is no way to edit or append a correction to a tweet, and once it has been retweeted, those 140 characters take on a life of their own. A follow-up tweet with the correct information might not be seen by the same people.
"You want to respond as quickly as possible. Deleting the tweet is a good approach, but even if you delete it it's obviously already out there," said social media expert Krista Neher.
The AP incident is not the first time a tweet has influenced markets. In August 2012, an Italian journalist set up a fake Twitter account for a member of Russia's government and tweeted that the president of Syria had been killed, causing brief fluctuations in the oil markets. The journalist was an experienced Twitter hoaxer, having previously posted fake tweets about the death of the pope and Fidel Castro and established a number fake accounts for world leaders. He claimed he did it to prove how unreliable social media is for getting accurate news.
A tweet doesn't just trigger financial panic, it can also strain diplomatic relations, as the U.S. Embassy in Cairo found out in April when the official Twitter account posted a link to a Daily Show segment critical of Egyptian President Mohammed Morsi.
In March, someone posing as the U.S. ambassador to Moscow tweeted a criticism of the Russian presidential election process, which was picked up by the news media in Russia before it was revealed as a hoax. The U.S. government responded with official statements in both incidents.
"The speed at which information spreads is so much quicker than it used to be, and Twitter is such a big part of that," said Neher.
That was painfully evident late Thursday night during the manuhunt in Boston. A tweet mistakenly named a missing Brown University student as one of the suspects. Twitter latched on to the name and many users assumed it was true even though it hadn't been confirmed by authorities.
A faulty tweet also can have a negative impact on community or a family. Late last year a New Jersey teenager posted a plea for help on Twitter saying there was an intruder in her house and asking people to call 911. The tweet went viral as friends and strangers expressed genuine concern for her safety (though no one on Twitter actually called 911).
But it was quickly discovered that there was no home invasion. The teen had run away from home and was later spotted on security cameras buying a train ticket to New York City.
The fast-moving, viral nature of Twitter has its perils, but it can also be used for good. Twitter highlights the impact of single tweets in its Twitter Stories series, tracking Tweets that go viral and result in positive impacts and happy endings.