 According to a 1999 ADL report, the KKK's estimated size then was "No more than a few thousand, organized into slightly more than 100 units".In 2017, the Southern Poverty Law Center (SPLC), which monitors extremist groups, estimated that there were "at least 29 separate, rival Klan groups currently active in the United States, and they compete with one another for members, dues, news media attention and the title of being the true heir to the Ku Klux Klan".The formation of independent chapters has made KKK groups more difficult to infiltrate, and researchers find it hard to estimate their numbers.