All crimes are considered a violation of established law, but not all crimes have a readily identifiable victim. A so-called "victimless crime" often involves a violation of community standards or an illicit act against a government policy or agency. The term victimless crime is generally nowhere to be found in the legal system itself, but is more of a political or social description of a criminalized act of dubious severity. If there is no victim as such, the actual criminality of certain acts is often brought into question.

One common example of a victimless crime is the act of prostitution. Offering sexual favors in exchange for money is considered a crime in many places. Both the solicitor and the prostitute can be arrested for violating public decency laws. However, it is difficult to determine if there is an actual victim of a crime in a prostitution case. Both parties mutually agreed to the terms of the contracted service, so to speak, so neither could be considered victims in the eyes of the law. While prostitution may contribute to other domestic problems or personal vices, the act itself is considered a victimless crime.

Another type of victimless crime is drug possession and usage. While it could be argued, usually successfully, that a person under the influence of illegal drugs could cause damage to other people or property, the general possession or personal use of those drugs is considered a victimless crime by those seeking to repeal current drug laws. The user may be causing damage to his or her own body through habitual drug use, but the laws which make possession of these substances a criminal offense are largely written and enforced by non-users. The victim in this particular "victimless crime" is arguably the general public, since the criminalization of drugs makes it more difficult for drug-fueled criminals to commit other serious crimes.

Many white collar crimes are considered victimless crimes, although the act may cause real damage to a government agency or a large corporation. Tax evasion, for example, may cost the Internal Revenue Service a significant amount of grief and lost revenue, but the violator has not caused real financial damage to another person. Insider trading or other violations of SEC rules and regulations could also be considered victimless crimes, since they only involve an unscrupulous investor and the government agency which oversees public trading.

The concept of a victimless crime often plays a role in the proposed repeal of certain laws, especially the criminalization of drugs, prostitution and other vices. The argument presented by civil libertarians is that such laws only serve to punish citizens for personal lifestyle decisions which do not violate the legal rights of others. A citizen should be allowed to purchase and smoke marijuana legally, for example, because his or her private consumption in a private home does not affect anyone else's personal rights. Decriminalizing certain victimless crimes would reduce the prison population and take significant pressure off an overworked judicial system.