Authorship attribution is an important and emerging security tool. However, just as criminals may wear gloves to hide their fingerprints, so too may criminal authors mask their writing styles to escape detection. Most authorship studies have focused on cooperative and/or unaware authors who do not take such precautions. This paper analyzes the methods implemented in the Java Graphical Authorship Attribution Program (JGAAP) against essays in the Brennan-Greenstadt obfuscation corpus that were written in deliberate attempts to mask style. The results demonstrate that many of the more robust and accurate methods implemented in JGAAP are effective in the presence of active deception.