The Justice Department intervened in former President Donald Trump's lawsuit against Facebook to defend the constitutionality of Section 230, an internet communications law, according to court filings.

The federal intervention holds that the government has an "unconditional right to intervene to defend the statute," as it is always allowed in cases in which a law's constitutionality is at issue.

In July, Trump sued Facebook, Twitter and YouTube for suspending his accounts after posts he made during the Jan. 6 insurrection at the U.S. Capitol.

Trump brought the case in Southern Florida; the technology firms have countered, arguing the case must be brought in Northern California, where each of the platforms is based. A judge ruled the case must be moved to that jurisdiction, though the motion is still pending.

The Justice Department is often inclined to defend federal laws when their constitutionality is challenged, though the agency does occasionally decline and is required to inform Congress when it does so.

What is Section 230?

Section 230 is a subsection of the 1996 Communications and Decency Act that undergirds much of how social media operates in the U.S. The policy holds that websites are not liable for the content posted to their platforms, a principle that fueled the rise of modern social media.

The principle has come under scrutiny in recent years amid growing criticism of the technology industry across the political spectrum. Conservative activists and politicians hold that Section 230 unfairly shields social media platforms from culpability in cases when they moderate content. That leads to claims of censorship from conservatives.

On the campaign trail, President Joe Biden said Section 230 should be "immediately revoked" because platforms like Facebook spread "falsehoods they know to be false." Biden has since raised concerns about misinformation on social media, arguing that a new framework is necessary for content online.

Big Tech companies counter that ending Section 230 outright would create worse social media platforms and, in some cases, force them to suspend service altogether.

Industry groups that represent Big Tech in Washington have called for updated regulations but often decline to go into further detail on what policies are most favored by technology platforms.

Follow Matthew Brown online @mrbrownsir.