According to the social networking giant, the ruling opens the door for courts to order the removal of content that is similar to the illegal speech, "meaning that something you posted might be removed even if you knew nothing about the earlier post that a European country had deemed illegal".
"Imagine something you wrote and shared on Facebook was taken down, not because it violated our rules, and not because it broke the law in your country, but because someone was able to use different laws in another country to have it removed," Monika Bickert, VP, Global Policy Management at Facebook, said in a statement on Monday.
"Imagine as well that your speech was deemed illegal not by a judge who carefully weighed the facts, but by automated tools and technology," she added.
The European Court of Justice has ruled that Facebook can be forced to remove content internationally.
The ruling arose from a personal defamation case brought by an Austrian politician.
The post in question shared a news article in which the Austrian politician had outlined her and her party's views on immigration, together with a comment from a Facebook user strongly critiquing the Austrian politician.
The court's ruling raises critical questions for freedom of expression, in two key respects, said Bickert.
First, it undermines the long-standing principle that one country does not have the right to impose its laws on another country.
"This is especially important with laws governing speech, because what is legally acceptable varies considerably in different parts of the world and even within the EU. The ruling also opens the door for other countries around the world, including non-democratic countries who severely limit speech, to demand the same power," said Facebook.
Second, the ruling might lead to a situation in which private internet companies could be forced to rely on automated technologies to police and remove "equivalent" illegal speech.
In a public Q&A, Facebook CEO Mark Zuckerberg had said that the ruling sets a "very troubling precedent".
"We have had precedents but we have successfully fought them. This is one where a lot of the details of exactly how this gets implemented are going to depend on national courts across Europe, and what they define as the same content versus roughly equivalent content.
"This is something we and other services will be litigating and getting clarity on what this means. I know we talk about free expression as a value and I thought this was a fairly troubling development," Zuckerberg added.
( With inputs from IANS )