For certain sensitive websites (e.g. domain registrar) I change passwords once a year or so, because there's really no guarantee that administration would 1) no

For certain sensitive websites (e.g. domain registrar) I change passwords once a year or so, because there's really no guarantee that administration would 1) notice a breach early or at all, 2) fully understand the scope/severity, or 3) even notify their users about a breach.