Patent trolls cost US companies $500 billion.

Researchers from Boston University have calculated that the damage caused to large companies by patent trolls since 1990 has exceeded $500 billion.

Patent trolls are companies that do not produce their own products, but instead make a living by litigating patent infringement.

Patent troll activity has become particularly active over the past four years. Companies have lost approximately $83 billion annually during this period. This amount is equivalent to a quarter of all research and development expenditures in the United States.

62% of lawsuits relate to software copyright infringement. To protect themselves from troll attacks, companies have recently begun purchasing patent portfolios.