This was, at least a few years ago, the case with Blizzard's Battle.net passwords. I picked a nice secure passphrase, but had to cut it off mid-word because of

This was, at least a few years ago, the case with Blizzard's Battle.net passwords. I picked a nice secure passphrase, but had to cut it off mid-word because of this truncation. (I think the behavior was for it simply to take the first 16 characters of whatever you typed in the password field, so typing the full passphrase didn't fail, but I wasn't confident that that would remain true in all cases, so I made a habit of only typing the first 16 chars.)