Prohibition of drugs
The prohibition of drugs through sumptuary legislation or religious law is a common means of attempting to prevent the recreational use of the prohibited drugs.While some drugs are illegal to possess, many governments regulate the manufacture, distribution, marketing, sale and use of certain drugs, for instance through a prescription system. Only certain drugs are banned with a ""blanket prohibition"" against all possession or use. The most widely banned substances include psychoactive drugs, although blanket prohibition also extends to some steroids and other drugs. Many governments do not criminalize the possession of a limited quantity of certain drugs for personal use, while still prohibiting their sale or manufacture, or possession in large quantities. Some laws set a specific volume of a particular drug, above which is considered ipso jure to be evidence of trafficking or sale of the drug. Drug prohibition is responsible for enriching ""organised criminal networks"", according to some critics while the hypothesis that the prohibition of drugs generates violence is consistent with research done over long time-series and cross-country facts.Some Islamic countries prohibit the use of alcohol (see list of countries with alcohol prohibition). Many governments levy a sin tax on alcohol and tobacco products, and restrict alcohol and tobacco from sales or gifts to minors. Other common restrictions include bans on outdoor drinking and indoor smoking. In the early 20th Century, many countries had alcohol prohibition. These include The United States (1920–1933), Finland (1919–1932), Norway (1916–1927), Canada (1901–1948), Iceland (1915–1922) and the Russian Empire/USSR (1914–1925).