line one's pocket

"How To Make Money In Japan" から引用します。
I retorted that in a "country of economic animals," the fact that the people --in most cases garbage collectors--who find bundles of 10,000 bills invariably hand them over to the police, is astonishing, too.
"If you know the Japanese so well, you must be able to explain to me why common people who are not exactly rich let go such a good chance of lining their pockets."
引用文最後の "lining their pockets" は着服する事を意味していると推測できますが辞書で確認します。
・Merriam-Webster's Online Dictionary: to take money freely and especially dishonestly
・Dictionary.com: to make much money, esp. in an illegal or questionable way.
・American Heritage Dictionary: Accept a bribe or other illicit payment, as in The mayor and his cronies found dozens of ways to line their pockets. This expression dates from the mid-1500s, when it was also put as line one's purse.
必ずしも悪い手段で懐を暖めるだけではない様ですが、普通はやましい方法でお金を手に入れる場合に使われるようです。本の著者が、日本人は清掃員がゴミからお金を見つけた場合でも警察に届けて "lining their pockets" はしない、と言ってくれたのですが、つい最近のニュースでそうでは無い日本人もいる事が分かりました。 残念。