Sitting in his Los Angeles home, Kuwaiti billionaire Bassam Alghanim received an alarming call from a business associate: Hundreds of his personal emails were posted online for anyone to see.

Mr. Alghanim checked and found it to be true, according to a person familiar with the matter. The emails included information on his personal finances, legal affairs, even his pharmacy bills, this person said.

Kuwaiti billionaire Kutayba Alghanim, above, allegedly commissioned hackers to copy emails of his brother, Bassam.

A cottage industry of so-called hackers can be hired to break into emails for as little as $150, Cassell Bryan-Low reports on digits.

That led to another surprise. Mr. Alghanim discovered the person who had allegedly commissioned the hackers was his own brother, with whom he is fighting over how to divide up billions of dollars of joint assets. Mr. Alghanim’s lawyers allege in court filings that the brother hired investigators to illegally access his email with the help of Chinese hackers. Cost to hire the hackers: about $400.

Although the brothers’ feud involves big money, documents filed in two civil cases in September 2009 suggests just how simple and affordable online espionage has become. Computer forensic specialists say some hackers-for-hire openly market themselves online. "It’s not hard to find hackers," says Mikko Hypp