President Donald Trump has been mulling over the idea of ending birthright citizenship by executive order, in part to stop cases like one last week where a Chinese national pleaded guilty to immigration fraud and other charges involving her “birth tourism” operation.

Wealthy foreigners have turned to birth tourism as a means for their children to obtain U.S. citizenship — and all the benefits that come with it. Many of these operations are in California and South Florida because of the climate and proximity to coastal borders.

Dongyuan Li, who pleaded guilty to one count of conspiracy to commit immigration fraud and one count of visa fraud, ran You Win USA Vacation Services Corp. out of Irvine, Calif., from 2013 until March 2015, according to the plea agreement as reported by Li’s is the first case in a string of 19 birth tourism indictments that has pleaded guilty.

The details of Li’s business reveals a lucrative and dishonest operation. Apparently, Li charged anywhere from $40,000 to $80,000 per customer and she alone received over $3 million through wire transfers from China, according to the indictment. She ran her business out of 20 apartments located in Irvine.

The company would coach customers on ways to falsify visa documents and lie to pass the U.S. Consulate interview in China so they could stay in the states for up to three months instead of two weeks. The plea reveals customers were taught how to conceal their pregnancies to trick U.S. customs. Many would also enter the U.S. through Hawaii before flying to the mainland because Li believed it was easier to get through customs on the island state instead of through a busy location like Los Angeles.

Li is facing a maximum sentence of 15 years in federal prison after already forfeiting over $850,000 along with other assets like her residence in Murrieta, Calif., and several luxury cars.

However, the act of travelling to America and giving birth is still technically legal.

In August, Trump said that the administration is looking into ending birthright citizenship through executive order, but many lawmakers from both sides of the aisle have pushed back against such a drastic change to U.S. immigration laws.