WASHINGTON (NEXSTAR) — The Federal Trade Commission says Google has agreed to pay a record $170 million fine for violating federal laws against tracking and selling online advertisements targeted to children on its subsidiary YouTube.

It’s the largest-ever penalty under the Children’s Online Privacy Protection Act. The FTC says that for years, YouTube ignored the law and collected user information from children to better target them with special ads. The FTC chair said the fine is about equal to the profit generated from the ads aimed at kids.

“This case sends strong messages to third parties like YouTube, channel owners and the business community as a whole,” FTC Chairman Joseph Simons said.

“YouTube cannot pretend that it’s not aware of the content on its platform and hope to escape liability,” Andrew Smith, the director of the FTC’s Bureau of Consumer Protection, added.

Critics say the fine is simply a slap on the wrist.

“It’s a parking ticket, not a punishment, said Ed Mierzwinski of the advocacy group U.S. Public Interest Research Group, which was among about a dozen groups that flagged YouTube’s violations earlier this year. “I think it sends a message that if you’re a big, powerful company, the FTC’s got your back.”

Sen. Ed Markey, D-Mass., who has supported stronger child privacy laws, agrees.

“This settlement makes clear that this FTC stands for ‘Forgetting Teens and Children,'” he said in a statement.

But website trade organization NetChoice, which represents Google, says the fine is reasonable.

“The idea of penalties is not to completely destroy a company,” spokesman Carl Szabo said.

He said the bigger concern is new rules that will require YouTube to get parental consent for all children’s content, arguing those rules will hurt ad sales and slow innovation.

YouTube has agreed to follow the rules, which go into full effect in four months.