10 states sue Google, allege digital ad monopoly

An alleged digital advertising agreement between Google and Facebook to curb competition is under scrutiny, according to a CNBC report.

Five details:

1. On Dec. 16, 10 states filed a lawsuit against Google, accusing the tech giant of having a monopoly in the online ad market because it controls both the buy and sell sides. The suit also accuses Google of connecting ad products unlawfully within its ad products.

2. The lawsuit alleges Google required publishers to use Google-owned tools to operate on its ad exchange.

3. Facebook is named as a co-conspirator in Google's efforts to reduce competition in exchange for a favorable position in auctions for mobile app advertising inventory, according to the lawsuit. Spokespeople for Google and Facebook denied the allegation to The Wall Street Journal.

4. States involved in the lawsuit are Texas, Arkansas, Idaho, Indiana, Kentucky, Mississippi, Missouri, North Dakota, South Dakota and Utah.

5. A Google spokesperson cited declining digital ad prices in the last decade and the company's below-industry average ad tech fees as proof of industry competitiveness in the CNBC report.