When used in a sexual context, groping is touching or fondling another person in an unwelcome sexual way using the hands. The term generally has a negative connotation in many societies, and may be considered sexual assault, and terms such as frotteurism (or toucherism) may describe the practice of a person rubbing up against another person, typically using their sexual parts. Touching a consenting person's body during sexual activity, massage, or medical examination is not usually considered groping, though the term is sometimes used to include clumsy, selfish, or inappropriate sexual touching. Areas of the body most frequently groped include the buttocks, breasts, vulva and thighs on a woman, and the penis, testicles and buttocks on a man. Gropers might use their hands, but pressing any part of their body against another person can be considered groping.
The incidence of groping varies around the world, and some countries have acquired a reputation for it. In some countries, it is common for a woman's buttocks to be pinched or slapped in a crowded area. In many countries, unwelcome groping or touching of any part of another person's body is illegal, but in almost all countries it is considered unacceptable behaviour. Italy used to have a reputation for men pinching women's bottoms, and the term groping could perhaps be applied, but it was not a common term at that time (mid-20th century, for example). Japan has a reputation for females being groped on trains and buses to the extent that the authorities have implemented anti-groping campaigns, which has received considerable media attention and been the subject of serious study in recent years. In parts of South Asia, including India,  Nepal  and Bangladesh,  public sexual harassment or molestation (often known as " street harassment ") of women by men is widely referred to as Eve teasing.
In Japan, men who grope women in public are called chikan (痴漢, チカン, or ちかん); and the term also describes the act itself. Crowded trains are a favorite location for groping and a 2001 survey conducted in two Tokyo high schools revealed that more than 2/3rds of students had been groped while traveling on them.  As part of the effort to combat the problem, some railway companies designate women-only passenger cars during rush hours.   While the term is not defined in the Japanese legal system, vernacular usage of the word describes acts that violate several laws. Although crowded trains are the most frequent targets, another common setting is bicycle parking areas, where people bending over unlocking locks are targets. Chikan is often featured in Japanese pornography.
This issue affects men in a different way. Since Japan has a very high conviction rate (99% by some sources), innocent men may have difficulty proving their innocence in court.  The film I Just Didn't Do It by Japanese film director Masayuki Suo, based on a true story, focuses on a male office worker acquitted of groping after a five-year legal battle.  The criminal courts have traditionally been lenient in cases of groping and have only recently made efforts to combat the social problem with tougher sentences.  
Groping is illegal when there is no consent. The charge can vary from state to state but generally is considered to be sexual battery, sexual groping, or unlawful touching. In some jurisdictions, groping is considered "Criminal Sexual Conduct", in the second to fourth degree, if there is no penetration.
- Florida: U.S. Customs and Border Protection (CBP) Officer Paulo Morales, 47, of Miami, pleaded guilty to sexually groping three women in his custody. Assistant Attorney General for the Civil Rights Division stated, “The Justice Department will continue to investigate and prosecute criminal civil rights violations committed by law enforcement officials”, and U.S. Attorney for the Southern District of Florida Wifredo A. Ferrer stated, “My office and the Department of Justice are fully committed to protecting the civil rights of our citizens from all types of abuses.” 
- Louisiana: Title 14, criminal law RS 14:43.1;  §43.1. Sexual battery: A. Sexual battery is the intentional touching of the anus or genitals of the victim by the offender using any instrumentality or any part of the body of the offender, or the touching of the anus or genitals of the offender by the victim using any instrumentality or any part of the body of the victim, when any of the following occur: (1) The offender acts without the consent of the victim.
- Michigan: THE MICHIGAN PENAL CODE (EXCERPT), Act 328 of 1931, 750.520e Criminal sexual conduct in the fourth degree; misdemeanor. Groping is considered Criminal Sexual Conduct specifically; (v) When the actor achieves the sexual contact through concealment or by the element of surprise.