Starting in about 1992, the government again resorted to repressive measures to stem the Brotherhood's increasing influence. In 1993, professional associations were placed under direct state control. In 1995 and 1996, over a thousand Brothers were arrested. Several were convicted by military tribunals to several years of hard labour; the main charge was that the accused were members of an illegal organisation that planned to overthrow the government. At the same time, the government directed a huge media campaign against the Brotherhood, accusing it of being a terrorist group. This reaction can best be explained as an effort to stave off a nonviolent, popular challenge to the regime's power, by preventing the Brotherhood from participating in elections. Similarly, in 1998, hundreds of student Islamic activists were arrested just before student union elections. The Brotherhood was particularly vulnerable to this crackdown because of its lack of support among the upper middle classes, industrial workers, and the poorest and least educated segments of Egyptian society.