Links for 2011-05-19

Internet users tap Facebook Inc.'s "Like" and Twitter Inc.'s "Tweet" buttons to share content with friends. But these tools also let their makers collect data about the websites people are visiting.

LinkedIn Corp.'s initial public offering roared out of the gates, pricing at $45 a share, the high end of underwriters' expectations, and giving the professional networking website a value of $4.25 billion.