Complex sentence: In April 2004 Sharman threatened legal action against Markus Kern for his distribution of the giFT Fasttrack plugin claiming that reverse engineering Sharman's Fasttrack network was illegal.
Split into simpler sentences: In April 2004 Sharman threatened legal action against Markus Kern for his distribution of the giFT Fasttrack plugin. Claiming that reverse engineering Sharman's Fasttrack network was illegal.