Use a PikePass, or else...

[patric]

It took seven (7) years for the Department of Public Safety to comply with an Open Records Act request for data on profiling by the OHP, eventually being forced by the Oklahoma Court of Civil Appeals for most of the information on the secretive OHP "Special Operations" unit that provides DA's with millions of dollars in confiscated cash and goods.
http://www.tulsaworld.com/news/article.aspx?subjectid=11&articleid=20090816_11_A1_AnOHPt433197

The most common tactic is watching cars who dont have PikePasses as they wait to go through toll gates and deciding if they want to search them. 

Once stopped, OHP has used their favorite drug-sniffing dog, aptly named "Kash", to sniff out money for seizure under the pretense that cash people carry must be "drug money".
http://www.tulsaworld.com/news/article.aspx?subjectid=13&articleid=010516_Ne_a1lawma&archive=yes

With most money tainted with Cocaine, it's a fairly easy (and common) practice.
http://ndsn.org/DEC94/DOG.html

CNN has done a series of stories on similar corruption: http://www.cnn.com/2009/CRIME/05/05/texas.police.seizures/index.html?iref=newssearch