good luck to you. I would think you will get nothing out of it.
Fighting against the big boys will cause you more harm than just let it go or write them a note.
What more, your pictures are being published in high profile or traffic website and they have credit you. Therefore, you should be thanking them rather than sueing them cos you get more exposure now. Do you think it is easy for your picture to be able to get publish in the website again? having a good relationship is better than making enemy or cause others to blacklist you.
Unless you are a professional working for agency or some companies and these pictures are used for other purposes then you might be able to justify a case for it. However, these are personal pictures taken for own keeping and will worth much lesser.
Even if you get $100, do you think it worth all the troubles and time to settle this?
Above are just my opinion. Cos i can see that people in SGP is kicking alot of fuss with such things.
You should see what these guys are saying
http://www.fredmiranda.com/forum/topic/909637