Guilty Until Proven Innocent?

Random Sobriety Checks/Drug Testing.. more unconstitutional violations of civil liberties, courtesy of millions of emotional mothers (http://www.madd.org/madd_programs/1229).  Guilty until proven innocent?

Woman arrested at a Sobriety Checkpoint.
http://www.youtube.com/watch?v=29AK3Iw01rQ

"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 4th Amendment of the Bill of Rights

How can this get more plain? Apparently, even the fucking supreme court agrees.
http://www.progress.org/drc44.htm

Here's some guy on youtube complaining about it.  Some of you might find this interesting.  If not, just ignore.
http://www.youtube.com/watch?v=0-YKOupojas

>>1  MADD is just like the million mom march.  A bunch of freedom hating fascists who won't be happy until your guns are banned and your liberties trashed.  Don't trust emotion stricken parents to make big decisions about government policy.  I'm rather sure a lot of the people (especially at MADD) would like to ban alcohol all together.  Fucking fascists.