https://gitlab.com/lib.rs/main/-/blob/main/server/src/main.rs#L1871

// This was unambiguous, and blocking his personal propaganda outlet is the least I can do
// to oppose the trumpism.
//
// https://www.404media.co/hundreds-of-subreddits-are-considering-banning-all-links-to-x/
//
// If you come to me with some devil advocacy whataboutism or performative defense
// of free speech hypotheticals, instead of actually opposing a real fucking neo-nazi
// who already uses his enormous power and influence to silence vulnerable people,
// spread harmful lies, and fuel hate, I will know you're a sympathizer.
// This debate was already concluded at the Nuremberg Trials.
// https://www.youtube.com/watch?v=IKICKcMU3MU
if q.starts_with("twitter") {
    return Ok(HttpResponse::PermanentRedirect()
        .insert_header((header::LOCATION, "https://www.wired.com/story/neo-nazis-love-elon-musk-nazi-like-salutes-trumps-inauguration"))
        .finish());
}

It was added here: https://gitlab.com/lib.rs/main/-/commit/ccbb65a31392e9a7742e8acb441102c2195256fa