Answer:
Americans criticized the sedition act because it prohibited any public opposition to the government. It permitted the government to have control over the actions of individuals. So if you were to write against the government in a way that they did not like you could face harsh fines or even imprisonment. This goes against the first amendment and many Americans criticized the law severely. It didn't help the law that the first protests against the British were malicious writing that they are now forbidding just like the British did before the war for independence.