Rational Survivability

(Ed.: Wow, some really great comments came out of this question.  I did a crappy job framing the query but there exists a cohesiveness to both the comments and private emails I have received that shows there is confusion in both terminology and execution of reverse engineering. 

I suppose the entire issue of reverse engineering legality can just be washed away by what appeared to me as logical and I stated in the first place — there is no implied violation of an EULA or IP if one didn’t agree to it in the first place (duh!) but I wanted to make sure that my supposition was correct.]

I have a question that hopefully someone can answer for me in a straightforward manner.  It  popped into my mind yesterday in an unrelated matter and perhaps it’s one of those obvious questions, but I’m not convinced I’ve ever seen an obvious answer.

If I as an individual or as a representative of a company that performs vulnerability research and assurance engages in reverse engineering of a product that is covered by patent/IP protection and/or EULA’s that expressly forbids reverse engineering, how would I deflect liability for violating these tenets if I disclose that I have indeed engaged in reverse engineering?

HID and Cisco have both shown that when backed into a corner, they will litigate and the researcher and/or company is forced to either back down or defend (usually the former.) (Ed:. Poor examples as these do not really fall into the same camp as the example I give below.)

Do you folks who do this for a living (or own/manage a company that does) simply count on the understanding that if one can show "purity" of non-malicious motivation that nothing bad will occur?

It’s painfully clear that the slippery slope of full-disclosure plays into this, but help me understand how
the principle of the act (finding vulnerability and telling the company/world about it) outweighs the liability involved.

Do people argue that if you don’t purchase the equipment you’re not covered under the EULA?  I’m trying to rationalize this.  How does one side-step the law in these cases without playing Russian Roulette?

Here’s an example of what I mean.  If you watch this video, the researchers that demonstrated the
Cisco NAC attack @ Black Hat clearly articulate the methods they used to reverse engineer Cisco’s products.

I’m not looking for a debate on the up/downside of full disclosure, but
more specifically the mechanics of the process used to identify that a
vulnerability exists in the first place — especially if reverse
engineering is used.

Perhaps this is a naive question or an uncomfortable one to answer, but I’m really interested.

Thanks,

/Hoff