What is something you've done that was questionable but legal?

I issued a (valid) DMCA notice to a small corporation who used the intellectual property of a colleague but did not pay them for it (they promised payment in writing, then just... didn't pay for a year or more). Their whole business website was down for a week or more as a result, as their registrar just took down their website without checking anything, and they didn't really have technical staff to resolve it.

The whole DMCA system is quite a broken mess, and is often (usually?) used unethically. However, it is possible to use correctly, even by private individuals. I'd be lying if I said I didn't enjoy it a little, that day.

One time I stole a balloon on free balloon day. The guilt still keeps me up at night.

I am an apartment building manager. Once, years ago, I was brought in to clean up after another manager who had quit/been fired for... let's just call it incompetence.

Anyway, there was a unit in the building that was occupied by a guy I never met or even saw, and the rent was months overdue. So I followed the required legal procedure to declare the unit abandoned. I spoke to neighbors. I posted notices, etc. Eventually, the unit was legally declared abandoned and I started the task of clearing out any property left behind.

The unit was very neat and tidy and full of nice stuff. Not the usual state of a rental that someone abandoned, and this should have tipped me off. But it didn't, and so I had everything hauled away. Furniture, electronics, clothes, the lot.

Then after 6 months I moved on to a different building. Later, I learned that the person who lived there was on active duty in the military, and that's why no one had seen them for months. Apparently, a neighbor had been entrusted to pay the rent but they had just kept the money for themselves, and lied to me when I inquired about the neighbor's whereabouts.

So, this poor guy comes back from overseas military service to discover that not only has he lost his apartment but also everything in it. And since I had followed the legal procedure, no law was broken (by me.)

Copied an example source code, which was under MIT+Apache 2.0 license, and created a derivative work under GPL, maybe that's questionable?

Tracing art back in highschool for an ungraded art project since it was just for the front and back of a crummy "sketch book" made entirely of white paper and staples.

For the vast majority of my life, I regularly paid mega corporations in a corrupt and evil industry to rape females with machines to impregnate them, then separate the children from their mothers shortly after birth so that I could drink the mammary secretions meant for those children (who were then murdered if they were male, or raised in deplorable conditions to become part of the process themselves if they were female).