Before 9/11, they had to show intent to defraud or some other crime before giving you a problem about using an alternate name.
Lots of people went by a nickname or their middle name, simplified or fancyfied the spelling of their last name, used pen names, etc.
To deposit a check in a business name, in California you had to go through a “Fictitious Business Name” procedure, registering it publicly. For a name ending in “Incorporated”, you had to file with the State as a corporation and meet certain standards.
Now, I believe that the DHS, etc, have required financial institutions, employers, and so forth, to get more information from you before doing business. At one point, feeling paranoid about giving a credit card over the Internet, I tried to get the kind of card you fund by putting in so many dollars, and then use for transactions. That would limit any damages. My bank made it clear that there was no way of doing that without my name, SSN, address, and I think Date of Birth, being on record. So I didn’t feel protected from identity theft.
I knew a couple of old cranks from before the 9/11 days that weren’t paying taxes and were using alternate names to receive money–one was a furnisher refinisher/auto repair guy, technically competent, that worked by the job. And I had known another guy who, when he came out of state prison, dropped a letter from his last name, drove for Goodwill for some years (“social handicap”), and later worked other driving jobs under his new name.
When they went over airport workers with a fine toothed comb, they were “smoking them out”, and you do wonder how many were dangerous lying fanatics, or security risks, and how many were just pore dumb SOBs trying to make a living.