Eugene Volokh found that only about two thirds of lawyers understand what orders of magnitude means. As in, “The population of the US is greater than that of Iceland by three orders of magnitude”. Which means of course . . . by a factor of 1000.
And I have to sadly agree with the take-away lesson he gets from this: Even though most lawyers know what the phrase means — including, reassuringly, Chief Justice Roberts — one shouldn’t use it in legal writing. After all, the purpose is to communicate, right?