A hacker called Comrade (.c0mrade) claimed to have breached the US Navy's official site and dumped a partial list of personal information and data on Pastebin.
The hack included the data profiles of 29 accounts on the website and 171 military email addresses and cracked passwords in alphabetical order, posted on a separate file.
"I'm going to be gracious here and not release the rest of the database as it features far more updated content," the hacker said, according to E Hacking news.
"Yes, we had complete control of the server a couple of summers ago, and yes, this can easily be retained, but frankly, I've got mad respect for anybody serving our country. The sole purpose of this intrusion was to let the government know that nothing is impenetrable."
According to security analysis group Identity Finder, the military alphabetical list in incomplete and may suggest that "the hacker intends to publish several hundred more accounts, after he cracks additional passwords".
"Almost all the cracked passwords were weak or dictionary words," Aaron Titus, privacy officer at Identity Finder, said. "As it is easier to crack weak and dictionary passwords, it is impossible to draw general conclusions about military password security, from this limited and skewed sampling. However, this breach highlights the importance of picking difficult-to-guess passwords.
In an interview with Cyber War News, Comrade, who is under 20, said hacking was "like an addiction" to him.
"Whenever I get a little bit, I simply want more," he said. "I also love to share my merits with the internet community. There's no reason not to.
"You can do it too, a webmaster can spend hours, weeks, months, or even years over-analysing code, but that doesn't mean they're completely safe," he said.
Comrade also talked about two past major hacks he claimed responsibility for - the Brazilian virtual Habbo Hotel website and a freemason site.
Habbo, one of the many online games often targeted by cyber-criminals, is a virtual world and a social networking site aimed at teenagers. Online thieves usually target users with fake web pages to capture usernames and passwords in "phishing" scams.
"Habbo was incriminated for their lack of trustworthiness and communication," said Comrade. "They didn't support our cause, so they got what they deserved."
As far as the freemasonry website was concerned, the hacker said it was "an open target due to their extreme lack of sense and constant wrongdoing".