$10\mathrm{.}5$ Peer$-$to$-$peer systems typically depend on untrusted and volatile computer systems for most of their resources. Trust is a social phenomenon with technical consequences. Volatility $($i$.$e$.,$ unpredictable availability$)$ also is often due to human actions. Elaborate your answers to Exercise $10\mathrm{.}4$ by discussing the possible ways in which each of them are likely to differ according to the following attributes of the computers used:

iv$)$ hardware or software errors.

Give two examples of possible incidents for each type of violation. Which of them could be described as a breach of trust or a criminal act? Would they be breaches of trust if they occurred on a personal computer that was contributing some resources to a peer$-$to$-$peer service? Why is this relevant for peer$-$to$-$peer systems?