ETA: Context here.
Look, it’s really fucking simple, okay?
Long But Short Version
Everything is under automatic copyright upon creation. Yes, everything. Text. Images. Video. Whatever. Everything.
If you want to use something, and it’s under copyright without another license, TALK TO THE CREATOR. They are a real person. Often they’ll have a contact form or email on their website. You know how to find a fucking website, or else you’re not a fucking journalist.
Subclause of previous: If you can’t find the creator for some reason (likely because the image was already stolen from somewhere else without attribution), then FIND ANOTHER PICTURE.
If something is under copyright and it has another license, such as GPL, LGPL, BSD, the Creative Commons family, etc., check those license terms. Most likely this means you can happily use the image with attribution with sometimes additional restrictions (such as: share-alike, non-commercial, etc), but if you don’t want to find out what licenses mean, YOU ARE NOT A FUCKING JOURNALIST.
“I advertised you for free” is such a lameass excuse. The whole fucking point of Creative Commons is not so that you can have things for free; the point is that it allows creators more flexibility in how to distribute their work. In any case, it’s the CREATOR’S CHOICE.
Learn how to use Flickr’s Creative Commons area. There are more than enough images here, including very pretty ones, for you to use with attribution (and for some of the sub-areas, additional restrictions, all easily coded by icon).
Really Short Version
Don’t be a fucking dick.
… for the swearing and random all-caps. Just… argh.