1792 was the ""annus mirabilis" of eighteenth-century radicalism": its most important texts, such as "Rights of Man", were published and the influence of the radical associations was at its height. In fact, it was as a result of the publication of the "Rights of Man" that such associations began to proliferate. The most significant groups, made up of artisans, merchants and others from the middling and lower sorts, were the Sheffield Society for Constitutional Information, the London Corresponding Society (LCS) and the Society for Constitutional Information (SCI). But it was not until these groups formed an alliance with the more genteel Society of the Friends of the People that the government became concerned. When this sympathy became known, the government issued a royal proclamation against seditious writings on 21 May 1792. In a dramatic increase compared to the rest of the century, there were over 100 prosecutions for sedition in the 1790s alone. The British government, fearing an uprising similar to the French Revolution, took even more drastic steps to quash the radicals. They made an increasing number of political arrests and infiltrated the radical groups; they threatened to "revoke the licences of publicans who continued to host politicized debating societies and to carry reformist literature"; they seized the mail of "suspected dissidents"; and they supported groups that disrupted radical events and attacked radicals in the press. Additionally, the British Government initiated the Aliens Act of 1793 in order to regulate the entrance of immigrants into Great Britain. Essentially, the Aliens Act enforced that aliens be recorded upon arrival and register with the local justice of the peace. Specifically, immigrants were required to give their names, ranks, occupations, and addresses. Overall, the Aliens Act reduced the number of immigrants into Great Britain out of fear that one of them may be an unwanted spy. Radicals saw this period as "the institution of a system of terror, almost as hideous in its features, almost as gigantic in its stature, and infinitely more pernicious in its tendency, than France ever knew".