Things generally fall into one of three categories: graphics and text I’ve created myself; things I’ve got a licence or the copyright holder’s permission to use – e.g. images used in captioned s-t-u-f-f; publicly available graphics – such as product and organisation logos. If it isn’t immediately obvious which is which, assume I own the copyright and ask me. (If I don’t own it, I’ll tell you.) The legalese regarding copyright can be read here.