(Stefano Rellandi/Reuters)

Something strange happened this week, just as sports fans settled down to watch playoff baseball and “Monday Night Football,” firing up their second screens for replays, snark and analysis. The Twitter accounts for two popular sports sites were suddenly deactivated, rendering unavailable two high-profile sources for quick video replays of licensed network broadcasts of games.

The move by Twitter came in response to complaints from the National Football League and others, raising the profile of a hotly contested and fluid corner of intellectual property law that impacts the way millions of fans today consume sports news and highlights.

With the rise in popularity of social media, fans no longer have to wait until late-night highlight shows to see video of towering home runs, thunderous slam dunks or bruising tackles. Users can record snippets of games from their home by simply pointing a smartphone at a television and uploading the video in almost real time to sites such as Twitter. Those posts are then shared by fellow fans and media sites, vastly expanding their reach.

Some sports leagues routinely file complaints against users they feel infringe on their various copyrights by publishing content without permission. This has become an area of particular concern with social media sites that rely on or encourage the use of video.

But Monday night’s step by Twitter raised the stakes, as the social media giant targeted the account of Gawker Media’s Deadspin, the popular sports blog that has more than 887,000 Twitter followers. Fans immediately took to Twitter to engage in a spirited debate about intellectual property, many casting the NFL as a stern bully.

The two sites were suspended Monday night. [Screengrab]

While the Deadspin account was quickly reinstated, the Twitter account @SBNationGIF — an offshoot of Vox Media’s SBNation — was still inactive as of Tuesday evening.

Experts in Internet video and copyright law say it is a legal space increasingly difficult to monitor and protect as tens of thousands of social media users see fit to share video snippets from exclusive broadcasts of sports events that networks pay billions of dollars to secure. Like an endless game of whack-a-mole, even as leagues knock down some users for posting unauthorized videos, many, many more inevitably pop up elsewhere on the Internet.

“The practical challenge here is not easy to deal with,” said Ryan Vacca, the director of the Intellectual Property Center at the University of Akron School of Law. “With social media, there’s so many actors involved in the process, it’s very tough to police, especially if you're working in an industry that's time-sensitive as sports is. Unless you have a huge team ready to pounce and police these sites, it's going to be really difficult to be able to stop it 100 percent of the time.”

Some of the leagues contract with a third-party company to help police the issue, scouring the Internet for unauthorized usage of video, logos or other protected intellectual property. The NFL contracts with a London-based firm called NetResult, which monitors the Internet and files grievances on the league’s behalf.

The online database Chilling Effect Clearinghouse collects infringement and takedown notices. A search for “NFL” returns nearly 6,500 complaints, many containing hundreds of links, some related to video games or the unauthorized use of team logos or the NFL shield. Since the start of the NFL season five weeks ago, the NFL has filed at least 59 complaints, mostly against Twitter and Periscope, a live-streaming video service, in addition to a variety of sites promoting pirated broadcasts of games.

From the NFL’s perspective, it acted as any other entity that’s trying to protect its content. “The NFL, as part of its copyright enforcement program, sends take-down notices to protect its valuable content from piracy,” league spokesman Brian McCarthy said. “Like other content holders, we acted appropriately to safeguard our intellectual property.”

But Vacca said it’s increasingly difficult to determine what’s protected intellectual property and what’s legally considered fair use, a gray area of copyright law that in some cases permits limited use of copyrighted material without permission. In a recent decision in the U.S. Court of Appeals for the Ninth Circuit, a three-judge panel said that copyright holders “must consider the existence of fair use before sending a takedown notification.” Legal analysts say this could expand the interpretation of fair use and force leagues to think twice before filing a complaint.

“Look at the Vine example,” Vacca said of the Twitter-owned social media video service. “Those are six-second clips. They very well could be fair use, depending on the broader context, if they’re commenting on a particular play or athlete, it very well could be fair use.”

Using the example of sports highlights included on the nightly newscast, Vacca said Internet sites and social media users could re-publish videos, making a fair use argument that they’re providing commentary, analysis or journalistic value.

Leagues have different approaches and perspectives on the function of unauthorized video. Depending on whom you ask, allowing the user-produced videos to survive online is either bad business or good promotion. While the NFL and Ultimate Fighting Championships, the popular mixed-martial arts organization, have been proactive in protecting their video rights, Adam Silver, the National Basketball Association commissioner, has tacked in a different direction.

“The way we’ve looked at it, we've been incredibly protective of our live game rights," Silver said this year at the MIT Sloan Sports Analytics Conference in Boston. “But for the most part highlights are also marketing.”

“We have always believed that fans sharing highlights via social media is a great way to drive interest and excitement in the NBA,” Mike Bass, the league’s executive vice president of communications, said Tuesday. “Our enforcement efforts are not aimed at fans, but rather are focused on the unauthorized live streaming of our games.”

For others, it amounts to theft of prized content. Leagues routinely file complaints under the Digital Media Copyright Act, urging providers to remove unauthorized content. In recent weeks, the NFL and UFC sent notices of violations of the DMCA to Twitter over what amounts to a microburst pirating of videos.

Twitter declined to comment on any specific user or explain why it chose to suspend Deadspin’s account. “Like all of our industry peers, we do not proactively monitor content,” Twitter spokesman Nu Wexler said. “Rights holders report potential violations to us under the DMCA, we review their reports, and take action if the content violates our copyright policy.”

Twitter shared with The Washington Post two batches of recent DMCA complaints — 22 in all — related to the suspended accounts. There were 13 NFL complaints, primarily against Twitter for Deadspin’s football videos, a UFC complaint against Deadspin, and four complaints against @SBNationGIF by both the Big 12 and the Southeastern conferences in college sports, citing several instances of unauthorized GIFs.

Twitter has had a partnership with the NFL since 2013 and signed a new multi-year deal in August to bring video highlights to users. This season, the NFL has ramped up its efforts to supply clear, clean clips of big plays in close to real time.

A Deadspin editor declined to comment Tuesday, and a spokesman for Vox Media issued a statement that read in part, “We take copyright infringement issues seriously and always try to keep our use of unlicensed third party footage within the bounds of fair use.”

While the short video snippets online might not threaten television ratings, they could have a bigger impact on pay-per-view events. UFC officials, who did not return a request for comment, have been particularly aggressive to protect its videos.

“If you put up a GIF on a page or site, you can expect a notice within minutes,” said Luke Thomas, senior editor of MMAFighting.com, part of SBNation’s network of sports sites. “They're extremely aggressive about it.”