If a computer is a laptop with a built-in battery, then there is no risk (unless the battery is absolutely dead) of unplugging it from power. However, of a non-battery backed up PC (like an iMac or a Desktop), there could be problems, depending on PC configuration and current activity.
Updated February 23, 2017. The Haymarket Riot in Chicago in May 1886 killed several people, and resulted in a highly controversial trial followed by executions of four men who may have been innocent. The American labor movement was dealt a severe setback, and the chaotic events resonated for many years.
On this day in History, The Haymarket Square Riot on May 04, 1886. Learn more about what happened today on History.