TikTok and its China-headquartered parent company ByteDance sued US Attorney General Merrick Garland on Tuesday over a recently signed law forcing ByteDance to sell its popular social media app under threat of a ban. The plaintiffs claim the law violates the companies’ First Amendment free speech rights while US officials claim it is necessary for national security.

In the 65-page suit, TikTok and ByteDance claim that it would not be possible for ByteDance to divest from TikTok in the 270-day timeframe required by the law. The companies allege that “sponsors of the Act were aware that divestment is not possible,” and as a result “the Act will force a shutdown of TikTok by January 19, 2025.”

The plaintiffs further assert that the act:

[W]ould allow the government to decide that a company may no longer own and publish the innovative and unique speech platform it created. If Congress can do this, it can circumvent the First Amendment by invoking national security and ordering the publisher of any individual newspaper or website to sell to avoid being shut down.

The companies say that the act violates the First Amendment to the US Constitution as, according to the suit, the act does not safeguard national security nor is it”narrowly tailored” to that effect. Aside from the First Amendment claims, the lawsuit says that the act is an unconstitutional bill of attainder, which is an act that declares someone guilty of an offense and punishes them without trial. It also claims that the act violates the Fifth Amendment’s Due Process Clause as the act specifically names and singles out TikTok and ByteDance. Lastly, the suit alleges that the act is an “unconstitutional taking” under the Fifth Amendment, which provides that private property shall not be taken for public use without just compensation.

H.R.815, the act which establishes the ban, designates apps operated by TikTok and ByteDance as “foreign adversary controlled applications.”  The act bans these apps unless the owner of such an app divests from it within 270 days, subject to a one-time 90-day extension.

US President Joe Biden signed H.R.815 into law nearly two weeks ago after it passed both the US House and Senate as part of a foreign aid and sanctions package. The bill garnered bipartisan support in both chambers over fears that China would use TikTok to gain access to Americans’ personal information. Once the bill was signed, TikTok decried it as “unconstitutional” and vowed to challenge it in court.

The US State of Montana previously passed its own TikTok ban in May, but a federal judge temporarily blocked the ban in December over free speech concerns.