Software agents extend the current, information-based Internet to include autonomous mobile processing. In most countries such processes, i.e., software agents are, however, without an explicit legal status. Many of the legal implications of their actions (e.g., gathering information, negotiating terms, performing transactions) are not well understood. One important characteristic of mobile software agents is that they roam the Internet: they often run on agent platforms of others. There often is no pre-existing relation between the "owner" of a running agent's process and the owner of the agent platform on which an agent process runs. When conflicts arise, the position of the agent platform administrator is not clear: is he or she allowed to slow down the process or possibly remove it from the system? Can the interests of the user of the agent be protected? This article explores legal and technical perspectives in protecting the integrity and availability of software agents and agent platforms. © Springer 2004.