It's a good time to be in the internet piracy business. Affordable streaming services are more popular than ever, but it's clear that illegal download sites like the Pirate Bay and Kickass Torrents provided free content, and made money, at an unparalleled rate in 2015.

The year didn't start off that way. After the Pirate Bay, the longest-running and most popular illegal torrent site, was shut down in an international police raid in November 2014, it looked like the piracy ecosystem was in trouble.

But the Pirate Bay, Kickass Torrents, Popcorn Time and other heavyweights all rebounded from investigations and malicious software infestations to end the year with more influence than ever. While that might be good news for the millions who visit each site every day — who doesn't love a free movie, after all? — the proliferation of criminal sites, and the lack of a clear enforcement strategy, actually puts users at risk.

Pirate Sites Refuse to Walk the Plank

The Pirate Bay returned from the dead in late January, two months after Swedish authorities knocked the site offline and confiscated many of its servers. By then the resurgence was largely symbolic, as users flocked to competing torrent sites or accessed the Pirate Bay's back catalog via proxy and mirror pages. But then EZTV, one of the most reliable TV providers, went offline, followed by Project Free TV and then the bombshell that Popcorn Time voluntarily shut down after legal pressure from the Motion Picture Association of America.

All of those sites were back online in one form or another on the final day of 2015. Even Kickass Torrents, a site nearly as infamous as the Pirate Bay, remains online after spending time on Google's Harmful Programs list, rendering it inaccessible for many users, for hosting ads inundated with malicious software.

“If you're a big copyright advocate, you're probably surprised that blocking the Pirate Bay doesn't have much of an effect at all,” said Brett Danaher, an assistant professor of economics at Wellesley College and the author of a 2015 study on website blocking. “But when you block just one website, you don't reduce piracy a lot. When you block more sites at the same time, that has more of an effect.”

Downloading on the Rise

The Matthew McConaughey space flick “Interstellar” was the most stolen movie of the year, with 46.7 million downloads from Jan. 1 to Dec. 25, 2015, according to the anti-piracy company Excipio. Compare that to “The Wolf of Wall Street,” which topped the 2014 charts with just over 30 million illicit downloads. That figure wouldn't be enough to break the top 10 in 2015, and would make the Leonardo DiCaprio film (and its $392 million international gross earnings) only the 11th-most-downloaded movie in 2015, just ahead of “Focus” ($159 million international gross).

Many of the people who download movies illegally are located in countries without viable legal streaming options. In order to watch “Interstellar,” though, American viewers would need to pay between $6.99 (on Amazon) and $14.99 (on iTunes). Little research has been released on what, if any, price threshold would be enough to convince a would-be consumer to visit the Pirate Bay, though even that $6.99 figure might be enough.

“There is evidence that when cheap, legal and convenient options are available people tend to not pirate,” said Joel Waldfogel, a professor of applied economics at the University of Minnesota, who researched the effect of piracy on Hollywood income. “When there's an inexpensive and convenient way to get stuff for free, people tend to pirate, especially when there's a relatively small risk of getting caught.”

Financial Impact

Estimates of dollars lost to piracy vary widely, mostly because downloads are untracked. The Recording Industry Association of America pegs the annual loss at $12.5 billion in the U.S. alone, including 70,000 job losses and $2 billion in lost wages. Before that, the MPAA suggested the figure is actually $58 billion. Both numbers have been roundly criticized, and most independent researchers seem to agree the total losses between 1999 and 2010 are somewhere closer to $8 billion.

The cost to downloaders has become much more clear. Every month piracy websites expose 12 million users to malicious software — including sophisticated ransomware and remote access trojans — that enable attackers to access victims' personal information, according to data provided to International Business Times earlier this month. Hackers then resell users' stolen information for $20 to $45 apiece, depending on the type of data. That was enough for piracy website administrators to make $70 million in 2015 alone.