While there is not a law preventing IP scanning in the U.S., the person who scans the network without prior permission can be served with a civil lawsuit. Obtaining any information without previous permission is considered a security breach. In Germany and some other European countries, the law criminalized dual-use security tools, making IP scanners illegal. On a private network, on the other hand, IP scanning is a legal and necessary part of the security system. This practice also allows for systems to find IP addresses that are not used anymore.