Free software program doesn't work exquisitely for you and furthermore, they would come with advertisements or different undesirable options, which could allow them to know that you're spying them.
Free software akusebenzi exquisitely wena futhi ngaphezu kwalokho, babeyothola phakathi izikhangiso noma ezinye izici engadingeki, which might let them know that you are spying them.