When finding a new apartment a few years ago I scraped a few sites. The variance in price is pretty interesting, ie. certain days of the week were better to press "Apply" on the rental form.

There is no strict need for this software to be anti competitive, now that prices are online they can do plenty of experimentation day to day on their own prices.

I also think the claim that they have some secret source of data from negotiated rents is not realistic, large companies don't really negotiate on rent.

However its bad news for the company that the lead developers of their two big software platforms appear to have gone on record in a pretty negative way.

Probably they got to greedy and have exposed themselves to anti trust by commingling data.