Hi Theodora:
The short answer is, it depends on whether the blogs and other sites can ligitimately claim a fair use of your picture under copyright law. Generally speaking, if they are deriving an economic benefit from using your picture, then the scale is weighted against a finding of fair use, but I would have to examine the uses of the picture before being able to advise you on this point.
If the use is not fair, then you may certainly have a claim for copyright infrigement. Please feel free to email me at bappel@balegal.com to discuss the matter further.
Brendan R. Appel
Answered on Feb 11th, 2013 at 5:06 PM