Classifieds website Backpage.com has been seized and shut down by the FBI.

The FBI confirmed Friday that agents also raided the Sedona home of Michael Lacey, the founder of Backpage.com.

Backpage.com has been under investigation for years for claims that the site facilitates sex trafficking on their adult ads page.

[READ MORE: Phoenix PD bust man with prostitution ad on Backpage.com]

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The site allows users to post ads for 'escorts' and investigators say many of the ads are actually for underage girls.

The FBI seized the website because it was allegedly being used to facilitate crime. The FBI has done this before with other sex trafficking websites and online pharmacies.

There are 17 victims named in the documents who are both adults and children who say they were forced into sex trafficking.

[READ MORE: Backpage.com executives plead Fifth in hearing on sex trafficking]

The charges were filed in Arizona because the website was founded and is maintained here and it’s also where Backpage.com's servers are located.

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The Department of Justice (DOJ) says almost every single sex trafficking case involves online ads, mostly from Backpage.com.

According to the DOJ, the biggest issue with these websites is that it facilitates sex trafficking for people who would have been to sheepish to pursue sex on the streets, especially to look for children.

There have been previous cases against Backpage.com that were thrown out.

The DOJ says the site has earned $500 million in revenue from prostitution since it was created.

[READ MORE: Phoenix officials raise awareness about human trafficking with new PSA]

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A report released by a U.S. Senate subcommittee in early 2017 stated that the National Center for Missing and Exploited Children's data indicates that 73 percent of the child-trafficking reports it receives were related to Backpage.com.

[RELATED: Documentary taking on sex-trafficking premieres in Arizona]

Site executives say they are protected by the Communications Decency Act which regulates pornographic material on the internet. Executives argue that the law states internet publishers cannot be held liable for content created by third parties.

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[RELATED: Seven arrested in online prostitution sting, police say]

But investigators say the site lost that protection when they alerted posters to key terms related to child sex trafficking. Investigators found proof of these alerts in internal Backpage.com documents.

The site even gave the third party posters a chance to rephrase their ads so they wouldn't be flagged for child sex trafficking. Some of the terms Backpage.com admins told posters not to use include "Lolita," young, teenager and even "Amber Alert."

The site's CEO, Carl Ferrer was arrested in late 2016 on pimping charges.

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[RELATED: John and Cindy McCain applaud the arrest of Backpage.com CEO]

Ferrer and other executives went before a Senate investigation committee in 2017 where they all invoked the fifth amendment. The charges against Ferrer were eventually dismissed.

The FBI's raid and shut down of the website is the latest development in the investigation into the website's role in sex trafficking.

U.S. Senator John McCain (R-AZ) released the following statement today on the seizure of Backpage.com:

“The seizure of the malicious sex marketplace Backpage.com marks an important step forward in the fight against human trafficking. This builds on the historic effort in Congress to reform the law that for too long has protected websites like Backpage from being held liable for enabling the sale of young women and children. Today’s action sends a strong message to Backpage and any other company facilitating online sex trafficking that they will be held accountable for these horrific crimes."

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