A group of Brazilian hackers attempting to attack the American National Security Agency (NSA) have apparently targeted Nasa by mistake.
The NSA has been hit by a range of claims in recent months that it used extensive and previously secret methods to monitor a huge amount of online and phone communications.
The accusations of cyber-spying have recently extended to Brazil, where the NSA allegedly spied on Brazilian President Dilma Rousseff's email and the state-run energy giant Petrobras.
The claims were based on the documents released by notorious whistle blower and former NSA contractor Edward Snowden.
Recently Rousseff called off a planned state visit to the US over the claims.
Official diplomacy aside there are also no shortage of hackers willing to take matters into their own hands.
But one hacker's attempts to strike back at the NSA ran into trouble recently, after he targeted (similarly named) NASA's website instead.
The hacker succeeded in posting a number of messages on official Nasa websites. He apparently just "picked the wrong target" according to Brazilian news portal Uol.
Nasa confirmed the attacks had taken place but said its sensitive data was never in any danger.
"At no point were any of the agency's primary websites, missions or classified systems compromised," said NASA spokesman Allard Beutel.
"We are diligently taking action to investigate and reconstitute the websites impacted during web defacement incident."
The incident recalled a famous comic by XKCD, which puts the hacking of public websites in perspective.