Here's a small example of writers (or broadcasters) getting it wrong.
A recent story on NBC's Today Show reported about a rape case in which the defense lawyer subpoenaed the victim's computer records, including all of her Google searches for the month before and after the rape.
The court initially ordered the victim to comply, but the victim risked contempt of court and refused on the basis that she was being victimized all over again. The court relented and denied the subpoena. The defendant was convicted and sentenced to 25 years in prison.
The story concluded by reporting that the trial court's decision had established precedent in the new area of law.
Stare decisis is a fundamental principle in American law brought over from the English Common Law. It means "let the decision stand." This guiding pricipal calls for courts to follow prior decisions in order to provide consistency and equal treatment of people in the same circumstances. Much of what lawyers do in briefs is to argue about how prior decisions apply to the case before the court.
But state trial court decisions do not establish precedent.
Only appellate decisions -- in fact only published appellate decisions -- establish precedent. State trial court decisions are not legal authority and cannot be cited as precedent. In other words, a decision by a trial judge in Marion County, Indiana is not precedent and cannot be cited to a trial judge in Jefferson County, Indiana -- let alone to a court in Ohio or Texas.
There is an exception for published decisions of federal district courts. Some federal trial court decision are published in the Federal Supplement or the Bankruptcy Reporter, as well as online. Those decisions generally deal with pre-trial procedural issues and carry some precedential value.
This is a legal technicality for most - but not for lawyers. Attorneys who have improperly cited "not for publication" decisions have suffered rebukes in published opinions, and even sanctions.
If you're writing about the law, you should try to get it right.