Lawsuit filed against rent-setting software RealPage
The same thing is happening with salaries. Most HR departments set salaries based on "market reference points" derived from data from salary survey companies like erieri.com.  But the HR depts also send their salary data to the salary survey companies (that is how they get a lot of their data).The result is all the companies in an industry are basically pooling their salary decisions and then carefully sticking close to what the others are paying. If the companies did this directly, it would 100% be wage-fixing. But somehow laundering it through an intermediate makes it legal.