Actually, altering the link can alter the destination because in many cases the page presented to someone who entered via an affiliate link is different than th

Actually, altering the link can alter the destination because in many cases the page presented to someone who entered via an affiliate link is different than the page presented when someone enters with a "naked" link. So if safe harbor is meant to protect a provider who doesn't make any changes to user generated content, then changing the link structure can in fact change the intent of the user.