When the US government uses the term "criminal alien", it means someone who is not a US citizen that has been convicted of a crime.
Twitter, meanwhile, thinks flying saucers and The X-Files.
On Wednesday, the Department of Homeland Security opened a new office, called VOICE, to "serve the needs of crime victims and their families who have been impacted by crimes committed by removable criminal aliens".
The centrepiece is a new hotline that victims can call for support and assistance. It was set up under the authority of an executive order on immigration from President Trump in January.
People began making clear exactly what people should not be using the line for.
But others noted the hotline was launched on Alien Day (a yearly promotional day backed by the Alien film franchise's producers).
And soon, people inevitably said they were beginning to call the hotline to report "criminal alien" activity of a different kind than that envisioned by Homeland Security Secretary John Kelly.
He said at the launch of VOICE on Wednesday that the victims were "unique, and too often ignored".
"They are casualties of crimes that should never have taken place," he said. "Because the people who victimised them often times should not have been in the country in the first place."
It's unclear how many people actually placed calls to the hotline, and several Twitter users reported long wait times to get through. But the US Immigration and Customs Enforcement (ICE) agency suggested it had impacted their service.
"There are certainly more constructive ways to make one's opinions heard than to prevent legitimate victims of crime from receiving the information and resources they seek because the lines are tied up by hoax callers," a spokesperson told Buzzfeed News
President Trump famously enraged Mexicans by suggesting in June 2015 that the country's immigrants were criminals and "rapists", and he has continued to take a tough line on illegal immigration since entering the White House.
Steep decreases in the number of people arrested while illegally crossing the border from Mexico in recent months have been touted by the administration as a sign that Mr Trump's policies are having the desired effect.
The government says the VOICE office will keep victims of alleged crimes by undocumented migrants updated as the suspect moves through the immigration system, including if they are deported.
Opponents of the administration's policies and rhetoric focusing on immigrants and crime point out that numerous studies have shown immigrants are less likely to commit serious crimes or be jailed than the native-born population.
The American Immigration Council says this "holds true for both legal immigrants and the unauthorised, regardless of their country of origin or level of education".