Like almost all crimes, they wouldn't care to prosecute most people. Tax avoidance is a crime. What percentage of people who lie on their tax returns get prosecuted anyway?
But if you are one of the unlucky few whom they decide to prosecute, you will have a bad time. Read the articles about Sirous Asgari. I don't have any good articles which tells the whole saga, but use this as the starting point and search more on the internet: https://www.theguardian.com/world/2020/apr/28/iran-scientist...
Recap of the saga:
An Iranian university professor (who had previously studied in the US and has ties to the US) requested a US visa. It was granted. Hew was arrested as soon as he entered the US. He was charged with wire fraud, visa fraud, and stealing trade secrets. After a lengthy trial, 2 years later, he was cleared of any charges and acquitted. But then ICE took him into custody because they had revoked his visa and he was in the US without a valid visa (please note that he had no choice in this, as he was forbidden from leaving the US while the trial was proceeding and he was taken into custody again immediately after the trial concluded. Real catch-22). Then he spent a couple of months in ICE custody and his frequent requests to be sent back to Iran was denied. He got infected with COVID-19 during this time. And finally in June, he was deported to Iran.
And this is the case of someone who was innocent. Imagine what would have happened if he were actually guilty. They gave him a visa so they could arrest him and charge him with visa fraud (among other things). Even when he was acquitted, he spent more time in jail because they retroactively revoked his visa. And most important of all, none of this even made front page. This is not one of those WTF cases that are so rare you might as well ignore them. Following the news on this over the years, the tone was always "yeah, nothing special about this case."
That's kind of a modus operandi for law enforcement in general. If they can't get you on a major crime, they are more than willing to vigorously enforce minor crimes to the fullest extent of the law.
But if you are one of the unlucky few whom they decide to prosecute, you will have a bad time. Read the articles about Sirous Asgari. I don't have any good articles which tells the whole saga, but use this as the starting point and search more on the internet: https://www.theguardian.com/world/2020/apr/28/iran-scientist...
Recap of the saga:
An Iranian university professor (who had previously studied in the US and has ties to the US) requested a US visa. It was granted. Hew was arrested as soon as he entered the US. He was charged with wire fraud, visa fraud, and stealing trade secrets. After a lengthy trial, 2 years later, he was cleared of any charges and acquitted. But then ICE took him into custody because they had revoked his visa and he was in the US without a valid visa (please note that he had no choice in this, as he was forbidden from leaving the US while the trial was proceeding and he was taken into custody again immediately after the trial concluded. Real catch-22). Then he spent a couple of months in ICE custody and his frequent requests to be sent back to Iran was denied. He got infected with COVID-19 during this time. And finally in June, he was deported to Iran.
And this is the case of someone who was innocent. Imagine what would have happened if he were actually guilty. They gave him a visa so they could arrest him and charge him with visa fraud (among other things). Even when he was acquitted, he spent more time in jail because they retroactively revoked his visa. And most important of all, none of this even made front page. This is not one of those WTF cases that are so rare you might as well ignore them. Following the news on this over the years, the tone was always "yeah, nothing special about this case."