Supreme Court Justices (Judicial Branch)
According to Title 28, Chapter I, Part 453 of the United States Code, each Supreme Court Justice takes the following oath:
"I, [NAME], do solemnly swear (or affirm) that I will administer justice without respect to persons, and do equal right to the poor and to the rich, and that I will faithfully and impartially discharge and perform all the duties incumbent upon me as [TITLE] under the Constitution and laws of the United States. So help me God.''
Sure. But taking recognition of facts commonly known, but not introduced into court, is a very common legal practice among judges and one that makes sense.
The liberal judges have taken it one step further to recognize foreign laws. In a very abstract view of things, I don't have a problem with that. It's the next step, that giving them some weight and influence over their decisions that gets very close to treason.
But if getting a new conservative judge confirmed for the SC is tough, just imagine what would happen if you tried to impeach a liberal one.