Yes, anything you place on the internet is subject to someone taking it, with or against your wishes.
Even years ago when I was creating some of my own styles from scratch, I shared some with a couple of people and before long they were being offered for sale as part of a package on Ebay!
There are scores of lyrics sites, all with identical versions of songs. They raid each other I guess.
That could have happened to me, in the pre internet days, when we where allways swapping styles.. (tough not selling them ourselves) and then certainly someone decided to sell the stuff he traded for free to people not in the circle of trading
These days when i get styles from someone, i allways ask if he minds me trading them with others again, works best.. tough we barely trade things these days as there is som much available for download..
Guess when your styles are in those free downloadable packages, everyone can get them and make their own package of them for selling them on E-bay..
But like said, these days i am much more inclined to check copyrights before using things.. Slowly things are changing where it comes to copyright protection of artists, and thats a good thing for those that create things..