You're violating the TOS for at least 3 of these sites... And by not providing attribution information I'm pretty sure you're violating the licenses of most of

You're violating the TOS for at least 3 of these sites... And by not providing attribution information I'm pretty sure you're violating the licenses of most of the images you're retrieving, a number of which are uploaded to specific sites and are therefore subject to the TOS and licenses provided on those sites, which your CMS/API whatever doesn't retrieve. Note that the penalty for copyright violations is theoretically $75k per violation and when a copyright is violated it doesn't matter if the material is royalty free.