be careful. i've known a couple people who travelled to Brazil and they NEVER felt safe while down there. Don't be stupid. Don't act like a "tough guy". They got guns. Even machine guns.
from travel.state.gov
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CRIME: Crime rates throughout Brazil have increased, but remain highest in the larger cities. The incidence of crime against tourists is greater in areas surrounding beaches, hotels, discotheques, bars, nightclubs, and other similar establishments that cater to visitors and is especially prevalent during Carnaval (Brazilian Mardi Gras). Occasionally, crime against tourists has been violent and has led to some deaths. While the risk is greater at dusk and during the evening hours, street crime can occur during both the day and night, and safer areas of the city are not immune. Incidents of theft on city buses are frequent, and such transportation should be avoided. Several Brazilian cities have established specialized tourist police units to patrol areas frequented by tourists. Recently, there has been a marked increase in crime in the capital, Brasilia. Armed robberies of homes and vehicles, some violent, and street crime are becoming commonplace. In Rio de Janeiro, efforts by jailed drug lords to exert influence over the city, has lead to a violent backlash against the local authorities and businesses (see separate section on Rio de Janeiro).
At airports, hotel lobbies, bus stations and other public places there is much pickpocketing, and the theft of carry-on luggage, briefcases, and laptop computers is common. Travelers should "dress down" when outside and avoid carrying valuables or wearing jewelry or expensive watches. "Good Samaritan" scams are common. If a tourist looks lost or seems to be having trouble communicating, he or she might be victimized by a seemingly innocent and helpful bystander. Care should be taken at and around banks and internationally connected automatic teller machines that take U.S. credit or debit cards. Very poor neighborhoods known as "favelas," often located on steep hillsides in Rio de Janeiro, are found throughout Brazil. These areas are sites of uncontrolled criminal activity, and are often not patrolled by police. U.S. citizens are advised to avoid these unsafe areas.
While the ability of Brazilian police to help recover stolen property is limited, it is nevertheless strongly advised to obtain a "boletin de ocorrencia" (police report) at a "delegacia" (police station) whenever any possessions are lost or stolen. This will facilitate the traveler's exit from Brazil and insurance claims. Carjackings are on the increase in Sao Paulo and other cities.
The loss or theft abroad of a U.S. passport should be reported immediately to the local police and the nearest U.S. embassy or consulate. U.S. citizens may refer to the Department of State's pamphlet, A Safe Trip Abroad, for ways to promote a trouble-free journey. The pamphlet is available by mail from the Superintendent of Documents, U.S. Government Printing Office , Washington, D.C. 20402, via the Internet at
http://www.gpoaccess.gov/, or via the Bureau of Consular Affairs home page at
http://travel.state.gov/.
SAO PAULO: While similar incidents may occur elsewhere, all areas of Sao Paulo have a high rate of armed robbery of pedestrians at stoplights. There is a particularly high incidence of robberies and pickpocketing in the Praca da Se section of Sao Paulo and in the eastern part of the city. As is true of "red light districts" in other cities, the areas of Sao Paulo on Rua Augusta north of Avenida Paulista and the Estacao de Luz metro area are especially dangerous. There are regular reports of young women known as "Mickey Finn girls" slipping knock-out drops in men's drinks and robbing them of all their belongings while they are unconscious.
RIO DE JANEIRO: The city continues to experience a high incidence of crime. Tourists are particularly vulnerable to street thefts and robberies on and in areas adjacent to all the main beaches in the city. Walking on the beaches is very dangerous at night. Recent efforts of incarcerated drug lords to exert their power outside of their jail cells have resulted in serious disruptions in the city, violence directed at the authorities and incidents of crimes against property, including after-hours shootings and explosions set off outside hotels and restaurants frequented by tourists. While these occurrences have not resulted in any injuries to U.S. citizens, visitors and residents alike should be aware that inconveniences such as closed shops and disrupted municipal services are likely. In Rio de Janeiro City, motorists are allowed to treat stoplights as stop signs between the hours of 10 p.m. and 6 a.m. to protect against holdups at intersections. All incidents should be reported to the tourist police, who can be reached at 511-5112.