United States v. Maynard, 615 F.3d 544 (D.C. Cir. 2010)

(law enforcement authorities cannot use global positioning surveillance (GPS) to track criminal suspects without warrant; such use violates suspect's 4th Amendment rights even though such usage successfully tracked suspect's movements lending credence to allegation that defendant involved in drug trafficking; case factually distinguishable from use of radio beepers used by law enforcement to track vehicles on public roads; court's opinion not applicable to "dragnet-type law enforcement practices").