In addition to those pesky foreign migrants destroying our environment by defecating on our land while growing marijuana:

“…high concentrations of human waste are left behind by smugglers, who come to the U.S. to care for the crops. This impacts wildlife, vegetation and water quality along rivers and streams. It also detracts from natural, scenic qualities and…” [1]

as well as destroying our precious ecosystem and rainforests (Silly me; i thought it was all those oil wells, the ceaseless logging of the rainforests for the USA and the pig iron industry, as well as forced farming and cattle production in rainforest regions, etc.) [2]:

“When people use illegal drugs, they are contributing to the destruction of land and countless species of animals and plants, placing the public at risk and supporting the disappearance of rain forests around the globe...” [2]

it now seems that this diabolical and treacherously evil-minded plant "placed on this Earth by Satan" can both CAUSE and PREVENT pregnancy simultaneously:

CAUSES TEEN PREGNANCY:

"Teens who are high on marijuana are less able to make safe, smart decisions about sex - including saying no," said Sarah Brown, Director of the National Campaign to Prevent Teen Pregnancy. "Teens who have used marijuana are four times more likely to get pregnant or get someone pregnant than teens who haven't." [3] 

PREVENTS TEEN PREGNANCY:

WASHINGTON (Reuters) - Sperm in men who smoke marijuana regularly lose stamina and burn out which may prevent conception, said a study released on Monday.

 The study by the State University of New York in Buffalo, New York, is the first to focus on the swimming patterns of sperm in men who smoke marijuana, the authors say.

"The sperm from marijuana smokers were moving too fast too early," said Lani Burkman, lead author of the study, in a statement.

"To attach itself to the egg, the sperm has to swim like mad -- that's hyper activation -- and they have to be vigorous at the right time," Burkman said. "Smoking marijuana messes up the natural regulatory system."

"The timing was all wrong. These sperm will experience burnout before they reach the egg and would not be capable of fertilization." [4]

What will this dangerous wonder plant do next?  In my humble opinion, if left unchecked, this scary plant which reportedly has been "sent by Satan" may not be satisfied with merely destroying our tiny planet; it may move into the outer reaches of space and cause the destruction of our entire universe!  - Ahhhh!!!!  Federal government of the United States, please save us all!

- - - - - - - - - - - - - - - - - - - - - - - -

FOOTNOTES:

[1] http://www.theantidrug.com/drugs_terror/drugs_environment.html
[2] http://www.ran.org
[3] http://www.theantidrug.com/drugs_terror/drugs_environment2.html
[4] http://www.whitehousedrugpolicy.gov/news/press03/031003.html
[5] http://www.cnn.com/2003/HEALTH/10/14/marijuana.fertility.reut/