Why is it difficult to enforce laws against intellectual theft?

because all intellectual theft occurs online and through digital networks
because most of the victims of intellectual theft are individuals
because some types of intellectual theft are legally protected
because much intellectual theft is committed in other countries

The best answer is: all intellectual theft occurs online and through digital networks.

Explanation:

Because the implementation is online and through the network, it is difficult to monitor and justify the safety of the victim and the theft. Internet is widely available to all individuals who has access to it. No matter what is the age, gender and nationality of the victim. It is difficult to maintain a law with its very wide scope and the audiences involved.