Amendment IV in the Bill of Rights
"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."
The US government cannot take anything from you without first having probable cause.
They may say that they are trying to keep schools safer, or that kids shouldn't be doing drugs.
That doesn't matter because the gov't can't take any of your possessions, even your urine, because the right to be secure in your possessions is one of your fundamental rights.
They may say that you cannot come to school it you do not submit.
That doesn't matter either because you are required by law to go to school.
No law can be passed that denies your Constitutional Rights.
If they did drug test people, then the students could, and should take them to court.
These Rights, as said in the 4th Amendment, "shall not be violated".
This won't be the first time it goes to the Supreme Court, and Mark My Words, it will go to the Supreme Court.
http://supct.law.cornell.edu/supct/html/94-590.ZO.html
This was a particular case where the school was able to fulfill its requirement that it "must demonstrate a `compelling need' for the program." 796 F. Supp., at 1363
Also, not every student in the school was allowed to be tested, but only the "students involved in extraciricular activities"(ie. athletics) were allowed to be tested because they were at an exceptional risk of injury if under the influence of drugs.
So, in order for a school to be able to test students it must be shown that there is a compellingly high incidence of drug use, and even if that is shown, the school can still only test the athletes.
All kids who are not involved in extraciricular activities were automatically exempt from testing.
Although I disagree with the gov't being able to do this, just to clarify, the gov't says testing is "to be private, confidential, non-punitive"
http://www.king5.com/topstories/stories/NW_011708WAB_random_drug_testing_LJ.2f34473c.html
But don't worry, this will get shot down in the Supreme Court as a direct violation of the 4th Amendment.