In the latest battle of music fans versus resellers, many were unable to buy tickets for an upcoming U2 concert despite being online the minute they went on sale.

Tickets for U2's "Joshua Tree" tour, kicking off in Vancouver on May 12, went on sale to the general public Tuesday morning and were sold out quickly. Minutes later, the seats appeared at prices higher than face-value on resale sites.

One fan, Phil Caines, was hopeful as he waited at the front of a line to make a purchase.

"I've always wanted to see U2," he told CTV News.

Another, David Vandas, logged on to his computer and was ready right at 10 a.m. to click his way to concert seats.

But both men were out of luck, and disheartened when they saw the seats available elsewhere for more money.

"I was just hoping to get a couple tickets for me and my wife, and it was instantly unavailable," Caines said.

"I feel like the system is broken… The average fan or fans that may not have as much financial means are really going to miss out. "

Vandas said he saw a ticket listed initially for $70 for sale on a resellers' site for around $400.

"When somebody's hacking the system for gain or greed, that system needs to adjust," he said.

A major barrier for would-be buyers is bots – software that lets brokers snap up tickets quickly. An investigation by New York's attorney general found that tens of thousands of tickets are purchased by bots each year.

"It took a single bot just one minute to buy more than 1,000 tickets to a U2 concert," Attorney General Eric Schneiderman said at a news conference last January.

But another issue uncovered in the investigation is that the number of tickets up for grabs in the first place isn't as large as fans might think. Many seats are held back for industry insiders and presales.

"For most popular shows, more than half of the tickets are not made available to the general public for sale," Schneiderman said.

In B.C., provincial officials have told CTV News the government doesn't plan to try to regulate ticket resales, saying that the responsibility lies with artists and promoters.

Some artists have attempted to crack down on resold tickets, including comedian Louis C.K. In the fall, he went as far as to warn fans that tickets sold on resale sites would be invalidated.

U2 ticket posted on resale sites also made headlines last week, when seats popped up on sites at inflated prices before they were even available for purchase.

Tickets went on sale early for super-fans who pay to be part of the band's online fan club on Jan. 11, but anticipation for the concert was so great that seats were showing up on sites like StubHub days before the pre-sale.

Postings included pricey VIP seats, put up for sale by those who expected to buy tickets once they went on sale, but didn't actually have them yet. The phenomenon is known as speculative selling.

With a report from CTV Vancouver's Maria Weisgarber