When Facebook Inc. chief executive officer Mark Zuckerberg appeared before the U.S. Congress in April, lawmakers warned that the era of self-regulation for social media was likely over. When the CEO of Alphabet Inc.’s Google, Sundar Pichai, testifies Dec. 11, he’s likely to hear the same admonition. Despite a plethora of complaints about big-tech companies from lawmakers and the public, only in the area of protecting privacy does it appear that new nationwide rules may be forthcoming.