Colombia is the most dangerous country in the world for union organizing. More trade unionists are murdered in Colombia every year than in the rest of the world combined. According to the Solidarity Center of the AFL-CIO, roughly 4,000 Colombian trade unionists have been murdered in the past 20 years, more than 2,000 of them since 1991. The ITUC reports that 78 trade unionists were murdered in 2006 in Colombia in a pattern of "selective, systematic and persistent violence" which amounts to a "fully fledged humanitarian crisis." Workers are also intimidated through the use of death threats, arrests, firings for organizing and many other forms of harassment.