Yes, jumping on or off a moving train—often called "train hopping" or "freighthopping"—is illegal in almost all jurisdictions and is extremely dangerous. In the United States, it is typically prosecuted as criminal trespassing on private railroad property, which is a misdemeanor that can lead to fines, a criminal record, or even jail time. Railroad companies, such as Union Pacific and CSX, employ specialized police forces to patrol yards and tracks specifically to catch and deter trespassers. Beyond the legal consequences, the physical risks are immense; the Federal Railroad Administration reports hundreds of deaths and thousands of severe injuries (such as limb loss) annually due to people falling under the wheels or being struck by trackside infrastructure. Modern freight trains are also much longer and more automated than those of the "hobo" era, making it easier for a person to be trapped or crushed without the crew ever knowing. For these reasons, law enforcement and railroad authorities maintain a zero-tolerance policy toward the practice to protect both the safety of the public and the security of the national supply chain.