Attorney General Jeff Sessions on Monday, fired a warning shot at sanctuary cities across the country, warning that any State or local governments seeking Department of Justice grants must prove that they are not sanctuary cities to receive those grants.

Sanctuary Cities are cities, counties and communities that have refused to work with Immigration and Customs Enforcement officials after detaining illegal immigrants. By federal law, they are required to inform the feds when they have an illegal immigrant in custody, even if he or she has not been convicted of a crime. Such cities include Los Angeles, New York and Chicago.

Sessions warned that such policies cannot continue as they make our communities less safe by putting criminals back onto the street. Sessions cited high profile cases like Kate Steinle, who was murdered in San Francisco by an illegal alien that had been deported 5 times and had 7 felony convictions and had only come back to San Francisco because he knew it was a sanctuary city.

Immediately after the press conference several prominent voices that advocate for sanctuary cities claimed that Sessions was not being truthful in his claims. California Senate President tweeted:

Lieutenant Governor Gavin Newson tweeted:

Understandably, this is an emotional issue and the effects it has on people lives is real. However, the cost to the tax payer is incredibly high. Per a report released in 2014, by the Federation for American Immigration Reform, it costs Californian tax payers alone 25.3 billion dollars annually to provide basic services to illegal immigrants and their dependents. That’s an incredible number that puts enormous strain on the system. It is time to put American citizens first and Sessions is on the right path to doing that.