Content-free chat app Yo has been hacked, just two days after it exploded into the public eye.
A Georgia Tech student, together with two of his room mates, claims to have hacked the app, which does nothing other than let users send the word "Yo".
Yo's founder Or Arbel has confirmed that the app is having "security issues".
"Some of the issues have been fixed and we are still working on the others," he added. "I cannot reveal any information about the hacks to prevent misuse of this information. We brought in a specialist security team to deal with the issues, and we are taking this very seriously."
According to TechCrunch, those phone numbers have been compromised in the hack. "We can get any Yo user’s phone number," Mike Butcher quotes the anonymous student hacker as saying. "We can spoof Yo’s from any users, and we can spam any user with as many Yo. We could also send any Yo user a push notification with any text we want (though we decided not to do that).”
Despite the security flaws, Yo has exploded in popularity since Wednesday. The app is now the 19th most popular free iPhone app in the UK, and the fifth most popular in the social networking category; and Arbel has reported that 4m Yos were send on Thursday, a four-fold increase on Wednesday's one million.
When Yo was launched, on 1 April, some wrote the app off as an April Fools Day joke. That impression wasn't helped by the fact that Apple had initially rejected the app, assuming that it was incomplete rather than deliberately minimalist.
But the app raised more than $1m in venture capital funding, and now has a business plan involving companies paying to send contextualised Yos. A trial is already in process: users who send a Yo to the WorldCup address will be yo-ed every time a goal is scored.
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