Client came back saying trademarks are logos/business names, not ideas like this image would represent. Although he loves the image, it ultimately doesn’t match the tagline. I’ve been scouring istock for a while, just can’t come up with anything.
No expert here, but I would probably first sit down with the client and go through what kinds of ideas and images he does associate with trademarks. (E.g. security, confidence, professionalism, law …) Rather than look for one, pre-made image, you could perhaps make a collage of different images and/or symbols that sum up the results of this discussion.