Four men accused of using a network of computers and automated software to buy up more than 1.5 million tickets online to concerts and sporting events and sell them at a $25 million profit were indicted on fraud, conspiracy, and computer hacking charges, federal prosecutors said on Monday. Bail is $2 million each.

Operating as Wiseguy Tickets, the men allegedly targeted online ticket vendors. They are accused of hiring programmers in Bulgaria to create a nationwide network of computers that impersonated individual visitors to the ticket vendor sites, flooding the sites at the exact moment that the tickets went on sale.

The network of computers, dubbed Captcha bots, automated and sped up the buying process by completing Captcha tests the sites presented that were designed to keep automated bots off the sites.

The men also are accused of creating shell corporations with fake domains and e-mail addresses and aliases to deceive the online ticket vendors.

The men allegedly operated the enterprise between 2002 and 2009. They are accused of purchasing more than 11,000 tickets to Bruce Springsteen shows alone during three months in 2007. In 2005, they allegedly bought more than 800 of the 1,000 tickets released for the Rose Bowl, according to the indictment.

The quartet face up to five years in prison on a conspiracy charge and up to 20 years on each of 42 counts of wire fraud, and a $250,000 fine on each of 19 counts charging gaining unauthorized access and exceeding authorized access to computers, and a 10-year prison sentence for each of six counts charging damage to computers in interstate commerce. In addition, each defendant faces a fine of $250,000 per count of conviction.