The Panama Papers proved they do it 🙃

What do you mean? Why do you think it’s unlikely?

In the same way that it's highly unlikely that there was widespread fraud in the 2020 election, even if people who have no evidence of it very strongly express that they think there was. When those people then attempt to subvert the election in order to install into power the person they say they think actually won (again, without any evidence of fraud), those people are committing crimes.

Based on the information at hand, we don't have any indication whatsoever of why Littlejohn purloined those tax returns and delivered them to media outlets, both contrary to existing law. Let's imagine he does say that he possesses evidence which suggests that each of those thousands of people had committed tax crimes so heinous that committing a crime and subverting the justice system is justifiable.

If those crimes were so heinous as to justify that, it would be the last thing you would do, not the first. First, you would report these heinous crimes - and the evidence you already have - to the very government agency you are contracted with. Second, you would report these heinous crimes, and the evidence you already have, and the IRS declining to investigate them to another agency, like the Justice Department, or to your Senators or Representative in Congress. Third, you would report the heinous crimes, and the evidence you already have, and the IRS declining to investigate, and higher federal departments and Congresspeople ignoring the whole thing to the media. (Never mind that all of those people willfully ignoring what has to be evidence of heinous tax crime is a textbook conspiracy theory.)

Then, when your "evidence" has shown to be nothing to the IRS, and the Justice Department, and your Senators and Congresspeople, and the media - then you commit a crime and steal thousands of peoples tax returns, and deliver those to ... yeah first you deliver them to the IRS, or maybe the next steps higher than that, not to the media first.

BUT THEN, THEN!! Then you can take the stolen tax returns and deliver them to the media. On the really off chance that you were actually right, and those tax returns demonstrate heinous tax crimes that nobody else could see without having those tax returns in their hands, it will all be worth it.

None of that happened. Littlejohn stole thousands of tax records and turned them over to media outlets. The end. If Littlejohn thinks that taking evidence to any or all of those other people and organizations shouldn't be the first step, and stealing the data and shoving it over to media outlets should be first, that's a conspiracy theorist.

But we don't know what Littlejohn thinks. We don't (yet?) know why he did what he did.

Maybe he tried to sell them, and wasn't having any luck, and decided to go for notoriety. Maybe he did sell some, and we just don't know about that yet. Maybe he was trying to get at Trump's returns specifically, and it made the most logistical sense to pull a ton of data along with Trump's - either to obscure the targeting of Trump specifically, or to be more likely to catch Trump's return inside of the data gathered up (if the desired data couldn't be located any other way). Maybe he didn't even know he had Trump's returns until after he collected this data. Maybe he never intended to "make off" with the data, but it ended up on a computer he had access to, or a backup, then he looked at it, then he realized he had Trump's returns. Maybe he was a conspiracy theorist.

All of those are "maybe," because they're all speculation. As is the speculation that

A contractor would have actual reason to believe that each of thousands of people had committed tax crimes so heinous that a justifiable action was to purloin each of their tax returns going back fifteen years, and then deliver that information to media outlets.

And every single one of those "maybes" is way more likely than a textbook conspiracy theory being true.

Apparently this guy thought and did exactly that.

If he "thought and did exactly that," he's a conspiracy theorist.