On Martin Luther King Jr. Day, millions across the nation honor the legacy of the civil rights champion--one that the FBI worked tirelessly to destroy.

After King delivered his famous "I Have A Dream" speech in 1963, the FBI labeled him the "most dangerous and effective Negro leader in the country," but their attack on the work of his lifetime didn't begin there.

According to CNN, tens of thousands of FBI memos from the 1960s disclose the law enforcement agency's "fanatical zeal" in their pursuit of the minister who stood on the frontline in the nonviolent fight against injustice. It's the reason why many couldn't help but resist the FBI's attempt to partake in the celebration of Martin Luther King Jr.'s life on Monday (Jan. 16).

Without fail, Twitter served up a swift reminder of the FBI's dark past with the late hero after catching wind of their commemorative tweet about the threat of injustice, no less. Check out some of the best reactions below: