This question's explanation and your answers so far.
情報の取扱いに関する不適切な行為a～cのうち, 不正アクセス禁止法で定められている禁止行為に該当するものだけを全て挙げたものはどれか。 a オフィス内で拾った手帳に記載されていた他人のIDとパスワードを無断で使い, ネットワークを介して自社のサーバにログインし, サーバに格納されていた人事評価情報を閲覧した。 b 自分には閲覧権限のない人事評価情報を盗み見するために, 他人のネットワークIDとパスワードを無断で入手し, 自分の手帳に記録した。 c 部門の保管庫に保管されていた人事評価情報が入ったUSBメモリを上司に無断で持ち出し, 自分のPCに直接接続してその人事評価情報をコピーした。
This lists only a, but b — obtaining another person's identification code without permission for the purpose of unauthorized access — is also prohibited by the Act as illegal acquisition of an identification code. Leaving out b makes it incomplete, so it is wrong.
正解 What the Unauthorized Access Prohibition Act prohibits is the act of unauthorized access — using another person's identification code (ID and password) over a network without permission to illegally log in to another person's access-controlled computer — together with related acts such as illegally obtaining, providing, or storing such identification codes. In a, another person's ID and password from a picked-up notebook are used without permission to log in to the company's server over the network, which is a typical act of unauthorized access. In b, another person's network ID and password are obtained without permission for the purpose of unauthorized access, which constitutes illegal acquisition of an identification code. Therefore, the acts that fall under the Act's prohibitions are the two acts a and b, and the correct answer is イ (a, b).
This lists all of a, b, and c, but c is the act of physically taking out a USB memory and copying it directly to one's own PC without going through a network. Since there is no breaking through of access control using another person's identification code, it is outside the scope of the Unauthorized Access Prohibition Act (it is a matter of theft or a violation of internal company rules), so including c is wrong.
This lists b and c, but a is a typical act of unauthorized access that must be included, yet it is left out, while c, which is outside the scope, is instead included. It is wrong on two counts.