Over 22,000 fans were glued to their seats at the National Stadium on Thursday night , watching Inter Milan beat Bayern Munich 2-0 in the International Champions Cup (ICC) Singapore tournament.

But on Facebook, more than a 100 users were glued to the account of BolaSport.com, a website run by an Indonesian sport and entertainment media company.

It was streaming the action from the seats live - and illegally.

The website had been launched only a week ago, and according to the website's employees, Thursday's stream was meant to be a trial run for future events.

"We are definitely very sorry (for what we did), we didn't really know that it was not allowed, so we will definitely learn from our mistakes." said a BolaSport representative, confirming that they stopped streaming immediately after being warned by ICC organisers.

Streaming the ICC game may have fallen foul of the law, but live streaming is not always illegal.

The distinction lies in the terms and conditions laid out by organisers, according to lawyer Bryan Tan, a partner at Pinsent Masons.

"When streaming a movie, copyright law protects the owner and makes the act of streaming an illegal one," he said.

In the case of Facebook Live, however, streaming is only illegal "if the act of taking the video is prohibited", for instance by contract.

ICC media guidelines sent to all attending media prohibit on-rights holders from filming during the game, or publishing videos of the matches online.

The ban also extends to fans. Ticket-sale terms state that video and sound recording of any kind is not permitted inside the venue.

Illegal online streaming has been a contentious issue of late, especially when it comes to football.

English Premier League organisers were recently awarded a British High Court blocking order for the upcoming season against illegal streaming sites, amid BBC surveys showing more than a third of fans watch the matches illegally online.

In Singapore, Internet Service Providers can block sites where large-scale infringement takes place. For example, movie streaming site, Solarmovie.ph, was blocked under this law last year.

"Content piracy hurts businesses and the livelihoods of people in the media industry," said a StarHub representative in response to a query by The Straits Times.

In Singapore, providers of illegal online streams may face fines of $10,000 per item and $100,000 in aggregate, as well as three to five years' jail.