In some circumstances it might be the case that political or legal actions need to have an effect on a system. For example, a court order might be given for the system to be shut down, or its data be made available for examination.
P2P systems can be more resilient to such actions due to their distributed nature. It would be impossible to shut down every node on a P2P network that spanned hundreds of thousands of nodes. Similarly it would be impractical to attempt to obtain the data that is held on every node.
The type of architecture used can affect a P2P systems compliance. Shutting down a truly decentralised system would be difficult (depending on its size), whereas a semi-centralised system can usually be significantly hampered by the removal of the central index node.
It might also be necessary to monitor a P2P system (by say a third party) to ensure it is complying politically and legally. Again this can also benefit from the type of architecture used, with it likely to be easier to achieve in semi-centralised systems.