ProPublica, the nonprofit journalism enterprise, has been the subject of some hysterical commentary since it reported on U.S. Rep. Mike Ross’ drugstore deal. This column gives you some useful background on the scope of its backers and its work. Its staff of 32 is headed by a former Wall Street Journal editor, Paul Steiger, who makes a comfortable $570,000 a year. At that rate, he can endure some ugly words from the DOG.