It appears Jeff Bezos’s streak as the only big tech robber baron not to be grilled by Congress is coming to a close. Cutthroat tactics are par for the course at Amazon, a company as closely associated with bullying subsidies out of local governments as it is with the burnout of its own employees. So it came it as little surprise that a Wall Street Journal investigation published last week found many long suspected: that the company uses seller data to inform its own private-label products.