Facebook acted like the US’s National Security Agency when spying on the social network's European users without consent or authority, according to a Belgian data protection watchdog.

Earlier, the Belgian Privacy Commission (BPC) filed a lawsuit against Facebook, which the BPC said is spying on people in "the very same way" that the US National Security Agency (NSA) does, according to media reports.

Speaking at a court hearing, Frederic Debussere, a lawyer representing the BPC, pointed the finger at Facebook, which is accused of breaching EU law and violating the privacy rights of internet users.

"When it became known that the NSA was spying on people all around the world, everybody was upset. This actor [Facebook] is doing the very same thing, albeit in a different way," Debussere said.

With the case already being closely watched by privacy watchdogs in other EU countries, including the Netherlands, Debusserre warned against yielding to Facebook intimidations.

"Don't be intimidated by Facebook. They will argue our demands cannot be implemented in Belgium alone. Our demands can be perfectly implemented just in this country," Debussere said.

It was reported that the BPC is currently threatening Facebook with a fine of 250,000 EUR (280,213 USD) per day for failing to respond to its demands.

Earlier this year, the BPC released a survey to show Facebook tracking logged-out users as well as non-users who visit sites that use plugins such as the like button; the survey said that the tracking is fulfilled without explicit consent and is out of line with Belgian and European privacy laws.

Facebook has more than once rejected these accusations, claiming that the data and conclusions in BPC’s privacy report hold no water.