PRESS DIGEST - Wall Street Journal - June 13

June 13 (Reuters) - The following were the top stories in The Wall Street Journal on Monday. Reuters has not verified these stories and does not vouch for their accuracy.     * Citigroup Inc waited as long as three weeks to notify credit-card customers of a hacking attack because it was conducting an investigation and producing replacement cards, according to a person familiar with the situation.     * Former Massachusetts Gov Mitt Romney, the front-runner in the