In reply to Augusto.

“Second, most plugins/themes on WP are GPL. While it may sound wrong, a lot of stuff on GPL clubs are actually legal to use.”

Not entirely true… All WP themes and plugins MUST have GPL license.

To be exact and comprehensive:

“According to the WordPress GPL (General Public License), all themes and plugins developed for WordPress must be released under the GPL license, regardless of whether they are free or premium. This means that anyone is free to use, modify, and distribute WordPress themes and plugins, and the source code must be made available to end-users.

This requirement is due to the fact that WordPress is itself released under the GPL license, which requires that any software that is derived from or distributed with GPL-licensed software must also be released under the same license. Therefore, all themes and plugins developed for WordPress must also be GPL-licensed in order to comply with the terms of the license.

However, it’s worth noting that premium themes and plugins can still be sold for a fee. The GPL license allows for commercial use of software, and developers are free to charge for their work. The key requirement is that the source code must be made available and that users are free to modify and redistribute the software.” ChatGPT

That said, and what’s missing from the above quote, with premium products, you can NOT distribute the license keys, otherwise and legally, you can do anything you want with the code you acquired.