Every now and then I get a flickr message from someone asking to use one of my pictures in some site or another, as I imagine do many people since I know of several people who have had similar queries. I don’t know about everyone else’s pictures, but the majority of mine have already got an Attribution-NonCommercial-NoDerivatives Creative Commons license on them, which means that I have already said you can use it and you don’t have to send me a message asking if you can use it. Especially not when your message directs me to an URL where I have to register on a site in order to click the box that says “yes, you can use it”. (I would have thought that having followed the personalised link from either my flickr account or email account would let you know that I am, in fact, me.)
So I’m afraid that people who do that instead of just using the damn picture are not going to get me replying with a yes. When it takes more effort than me either just clicking something or hitting ‘reply’ and typing “sure” or something like that, then no, you cannot use my picture. (I will add that this annoyance doesn’t include the messages you sometimes get where someone says “hey, I used your picture in an article, here is the link if you are interested”. I like that.)