I'm currently into editing photos, making them look like the ones you see on Tumblr with the text in the middle. I was paying for photos at first but this is just way too expensive for me to afford. I stumbled upon Pixabay, and they offer great photos for free. Thing is, they do not offer any kind of guarantee or license, they just assume that the uploader didn't steal it or something. so my question is- how can I actually verify that the photo is legit and that it didn't get stolen from Istock etc? Thanks.