Probative value, and countervailing adverse effects, of evidence

In law, the rules of evidence determine what evidence is admissible. For example, Federal Rule of Evidence 403 states, "The court may exclude relevant evidence if its probative value is substantially outweighed by a danger of one or more of the following: unfair prejudice, confusing the issues, misleading the jury, undue delay, wasting time, or needlessly presenting cumulative evidence."

This can become an issue during some child pornography cases.