User blog comment:Brandon Rhea/How we're testing the fandom.com domain migration/@comment-32911481-20181013074155/@comment-24155515-20181014154331

Actually, IPs can be static (largely unchanging) or dynamic (changing frequently), and they normally stay within a limited range in a certain geographic area.

The changes to dynamic IP addresses aren't so frequent that something like Checkuser has no applicability. Not that staff would use Checkuser for an action as benign as editing while logged out, I hope.