Complex sentence: As a result of Schlosser's criticisms of the food industry, he has been the victim of verbal attacks at book signings and public speaking events that he believes to be the work of citizens employed by large food corporations.
Split into simpler sentences: As a result of Schlosser's criticisms of the food industry, he has been the target of verbal attacks at his book signings and public speaking events. He believes such attacks to be the work of citizens employed by large food corporations.