Several weeks ago, my friend Jeff signed up for an online Twitter application that promised to delete his old tweets. It was advertised merely as a simple way to clear your online presence, but after Jeff used it, he noticed that his account began retweeting spam. Out of an abundance of caution, he deleted his Twitter account entirely. On Tuesday, Twitter announced steps it was taking to curb this exact sort of abuse.

Get in-depth coverage of current and future trends in technology, and how they are shaping business, entertainment, communications, science, politics, and society.