Plovdiv - the Old town : Featured photos taken in Bulgaria

I have taken this picture in 2001 i think , as well many other photos of my city Plovdiv and the area, which i found latter on many travel websites even on state owned websites. None of them asked me for any permision or credits.

Curious. is the picture in the public domain? I Understand that a picture at the least should be credited, and in particular if you don't own it. So, the first possible credit is to the owner, but if you don't know who the owner is, your next line of credit might be the source where you obtained the photo. If the source where you obtained the photo did not make any restrictions on the photo's use, they might be held to blame, but we should all make the effort to give credit where it's due.

Hi, why do you publish pictures without permision of the owner of this picture ?