Nobody knows his real name, what he looks like or where he lives, yet he has more than 1.5 million Twitter followers and is one of Saudi Arabia’s most ferocious political voices.

Known as @mujtahidd, this anonymous Twitter user has become famous for exposing the secrets of Saudi Arabia’s elites, including compromising details of the country’s royal family, upon whose continued rule a good chunk of U.S. Middle East strategy depends. In Arabic, “mujtahid” means an authoritative interpreter of religious law.

I want to contribute to change in Saudi Arabia. – mujtahidd

Mujtahidd’s forensically detailed and often sarcastic posts address sensitive issues like the royals’ over-the-top lifestyles, land appropriations, dodgy military deals and rigged public tenders. His main targets are King Abdullah and his sons, but there are also plenty of digs at Minister of Defense Salman bin Abdul-Aziz and the head of the Committee for the Promotion of Virtue and Prevention of Vice, Sheikh Abdul Latif Abdul Aziz al-Sheikh.

“I want to contribute to change in Saudi Arabia,” mujtahidd types. He takes another long moment to compose his next answer.

Contacting him was easy — he posts his Gmail address on his Twitter profile — and he answered my interview request promptly. While at first skeptical about OZY, he eventually agreed to a chat room interview with no preconditions — though he refuses to answer questions about friends or family, and often finishes answers by saying, “That’s all I can say.”

Asked if he is a man, a woman or a group of people, he answers, “I am a human,” but then admits being an “Arab male.” It’s difficult to guess much more. His tone seems cool and he uses emoticons sporadically.

“Exposing corruption contributes to accelerating political change. The more aware people are of what goes on, the more they will be ready to act,” he finally types.

Saudi Arabia seemed untouched by the tide of uprisings that swept the Muslim world in 2011. This wealthy desert kingdom of 28 million inhabitants is the world’s largest oil exporter. The Al Saud family has ruled since the 18th century and has grown to many thousands of members, in six major branches, who sometimes feud in the struggle for influence. The health of the king, about 90 years old, is uncertain.

The Al Saud family, who follow a strict interpretation of Sunni Islam known as Wahhabism, face increasing public scrutiny amid high youth unemployment, the looming threat of declining oil reserves — which account for half of the economy — and growing accusations of supporting jihadist terrorist groups like al-Qaida and the Islamic State, even though the Saudis are a bedrock Arab ally of the U.S. Political parties are banned. Dissidents are often thrown into jail or, in some cases, sentenced to death.

To quell a possible rebellion, the country’s rulers increased spending on social services and tightly limited free expression. Its Internet firewall is one of the toughest in the world.

He’s awfully cocky for a guy who looks like he’s way out on a limb.

But somehow Twitter has taken off. Saudi Arabia has 2.4 million active Twitter users, the highest number in the region — and, when it comes to political dissent, mujtahidd is leading the charge.

“The Saudi state is one of the most repressive in the world, so holding the royal family to account and challenging their control like mujtahidd does is helping promote freedom and transparency,” says Dr. Oz Hassan, from the Carnegie Endowment for International Peace.

But is mujtahidd for real? He’s awfully cocky for a guy who looks like he’s way out on a limb. He claims hackers constantly try to infiltrate his email account. Why hasn’t he faced the same treatment as Waleed Abu al-Khair, recently sentenced to 15 years in prison for speaking out against human rights abuses on social media?

There’s no doubt they know who he is. But it’s likely there are some factions in the royal family who support what he is doing and others who don’t. – Carlyle Murphy

“I don’t like to live in fear. I take all the right precautions,” mujtahidd writes. That he’s using Gchat somehow undermines the claim. Perhaps he’s a member of the royal family or is being fed information and protected by someone who is. He claims to be in Saudi Arabia, though there’s no way to prove that.

Is Saudi intelligence so incompetent that it hasn’t managed to track mujtahidd’s IP address during the three long years he’s spilled official secrets and embarrassed the royal family?

“There’s no doubt they know who he is,” says Caryle Murphy, a Saudi-based journalist and author of A Kingdom’s Future: Saudi Arabia Through the Eyes of Its Twentysomethings. “But it’s likely there are some factions in the royal family who support what he is doing and others who don’t.”

Even mujtahidd admits that. “They can’t reveal it because it would be too embarrassing,” he writes. “It would be like saying that the White House’s chief of staff is a Russian spy.”

Many of his tweets about the royal family’s publicly funded and eccentrically luxurious lifestyle have been titillating, if not scandalous. His posts describe the nitty-gritty details of life behind the palace walls, from the size of mansions and types of planes to the royals’ states of health and travel schedules.

Some predictions suggest access to high-ranking sources. In 2012, he tweeted about the intelligence agency director’s incompetence and the negative climate inside the agency. Shortly after, the Royal Court dumped him. But not all of mujtahidd’s prophecies come true. For more than two years, he has tweeted of an impending dispute within the royal family that could turn violent. Hasn’t happened yet.

His bold, often sarcastic tone makes him seem fearless. So does his habit of addressing the royals directly, like when he asked Prince Abdul Aziz bin Fahd, one of his favorite targets, “Is it true that your house in Jedda cost $1 billion but you charged $6 billion and pocketed the rest?” The royal answered by calling him a “slanderer” and a “hired tool.” (The prince, wealthy with a playboy image, was subject last month to a spectacular armed heist in Paris, where he reportedly lost 250,000 euros cash.)

Mujtahidd’s answer: “If I’m a hired tool, whoever is hiring me is doing a good job.” His special vitriol for Abdul Aziz adds to suspicions that he’s on a personal vendetta or trying to settle scores among royal family factions. Mujtahidd denies it. “He [Abdul Aziz] is simply the best example of royal corruption.” He won’t comment on whether he has ever met the prince.

Is he a renegade member of the royal family, a spiteful Saudi expat or a cyber-rebel despised by the establishment? Who can say?

“I won’t stop until Saudi Arabia has a regime change,” he says, meaning “a government that provides power sharing, accountability and transparency.” An unlikely turn of events anytime soon, but perhaps not impossible if the mysterious mujtahidd and others like him continue to chip away at the government’s legitimacy, one tweet at a time.