Compass, the real estate brokerage, claims that Zillow, the website that has 227 million unique visitors a month, has conspired to maintain a monopoly over digital home listings.

The rules of the real estate game are changing once again, with Zillow's blacklist taking effect. Homebuyers have options — here's what you can do.

On Monday, the real estate brokerage sued home-search website Zillow, accusing it of engaging in an anticompetitive conspiracy to maintain its dominance over digital home listings.