Intrusion Prevention Systems (IPSs) have long been proposed as a defense against attacks that propagate too fast for any manual response to be useful. While purely-network-based IPSs have the advantage of being easy to install and manage, research have shown that this class of systems are vulnerable to evasion [70, 65], and can be tricked into filtering normal traffic and create more harm than good [12, 13]. Based on these researches, we believe information about how the attacked hosts process the malicious input is essential to an effective and reliable IPS. In existing IPSs, honeypots are usually used to collect such information. The collected information will then be analyzed to generate countermeasures against the observed attack. Unfortunately, techniques that allow the honeypots in a network to be identified ([5, 71]) can render these IPSs useless. In particular, attacks can be designed to avoid targeting the identified honeypots. As a result, the IPSs will have no information about the attacks, and thus no countermeasure will ever be generated. The use of honeypots is also creating other practical issues which limit the usefulness/feasibility of many host-based IPSs. We propose to solve these problems by duplicating the detection and analysis capability on every protected system; i.e., turning every host into a honeypot. / text