The Alien and Sedition Acts marked an attempt by Federalists to suppress opposition at home. The acts gave the President power to arrest and deport any alien suspected of having
"treasonable or secret leanings."
This threatened many of the Jeffersonians who were not naturalized citizens.
The most controversial part of the acts was the section which established heavy fines, or even imprisonment; for saying anything false, scandalous or malicious against the government. Opponents claimed that this law abridged rights granted by the First Amendment. The Federalists responded that the First Amendment did not cover acts of sedition.
All together, 25 people were arrested under Alien and Sedition Acts; 10 were convicted and imprisoned.