The most frightening element of the Alien and Sedition Acts would be the apparent suspension of the First Amendment's entitlement to free speech. In an act of government repression and in the hopes of silencing dissent, the idea of a political body being able to strike down free speech and monitor what people say and think, with the power to imprison in the process would be quite scary. It also would scare me that the Constitution's promises as well as the fervor that inspired the Revolution on the grounds of freedom would be so openly betrayed through the acts of Government. I would be scared that my government's practice and its theoretical principles would seem to be incompatible, creating a lack of both confidence and credibility in both.
As an ordinary citizen, you would need to fear the Alien and Sedition Acts because you could get in serious legal trouble for simply saying anything that somebody thought was disrespectful of the government. Most of the people prosecuted under the Acts were not "ordinary," but some were.
My favorite story is one where Pres. Adams drove through a town and the local militia fired a salute as he passed. Someone said "there goes the President and they are firing at his ass." Someone else replied "I don't care if they fire it through his ass." That second person, who was a bit drunk, got arrested for a silly comment. That could happen to anyone under the Acts.
United States Congress passed 4 separate laws in 1798, all together called the Alien and Sedition Acts. An ordinary citizen would have much to fear because all 4 laws limited freedoms, including freedom of speech and expanded the power of the federal government over the individual.
The Naturalization Act extended the period of time that it would take an alien to become a citizen of the United States. Originally only 5 years, it would take a foreigner 14 years to obtain citizenship. This was worrisome especially after the passage of the Alien and Alien Enemies Act. Each of these gave the President and the Congress the power to deport aliens that they deemed "dangerous to the peace and safety of the United States."
The ordinary citizen would most fear the Sedition Act. The Sedition Act was used to prevent individuals from speaking out against the federal government's policies. Citizens could be imprisoned or fined for even disagreeing with the government, if the government defined it as "scandalous and malicious writing."
The true intention of the laws were to insure that any political opposition was kept quiet.
The greatest fear of these acts by the common citizen would be that the government was entitled to arrest or deport citizens and foreigners for speaking out against government policies. Politics of the past are not very different of politics today. There are politicians who would muzzle the voices of opposition given the opportunity. We must take great care not to repeat 1789 history and attempt to ban the views of those citizens who publically disagree and speak out against policies or politicians of an opposing administration. "Those who fail to learn and study history are apt to repeat it."