One of them helps himself to something, a little hairpin.

（彼らのうちの一人がある物を盗んだんだ。小さなヘアピンをね。）
　BBCドラマ「SHERLOCK」エピソード2 "The Blind Banker" より。事件解決後のホームズ＆ワトスンの会話。事件の全容について。

• "help oneself to something"に「勝手に取る、盗む」という意味があるなんて初めて知った！
• でもよく考えてみれば「どうぞご自由に」の "help yourself" （2011/11/12）だって、「お好きなようにどうぞ」→「許可を得なくていいから勝手にやってね」ってことだから、「許可を得ずに勝手に取っていっちゃう」（＝「盗む」）っていうのと発想は同じなのか。
  • Obviously he had been helping himself to the money.
  • He helped himself to the wages she had brought home.
  • He saw the money lying on the table, and he helped himself.
  • He helped himself to the money.
  • He'd been helping himself to the money in the cash register.