interesting info on Rubicon name use

The insurance company is correct:

I don't see how they can.

Of course they can, insofar as it relates to a narrowly defined range of services or products.

One may trademark any name, but one can only trademark a name for (and defend it within) a particular range of services and products, and only then if it is not in conflict with any similarly related mark. The Trademark office will not allow the trademark if its coverage is too broad.

DC could certainly file suit against anyone using any form of their trademarks, but whether they would win or not is an entirely different matter.

That is exactly where the issue of deep pockets comes into play; whoever has the deeper pockets usually wins. Just ask Nathan.