I've worked for the same small cluster of entrepreneurs, who are all very close personal friends, for my entire career. If you cold called people I'm professionally related to, and not on my list of references, then changes are very good that you're calling someone I currently work for or with. And chances are very good that my employer will find out.

Now, I have an excellent relationship with my company's owners and would certainly not get fired for such a thing, but others in my position might. And regardless, that's not information that you have any business giving out to my current employer. That's a discussion that must happen on my terms -- if my boss found out that I was interviewing other companies from your sloppy hiring practices, I would be pissed.

edit: Just realized that if you're going from LinkedIn contacts, you might be calling one of my current clients. That would be absolutely disastrous for myself and my employer -- yeah, go ahead and throw them under the bus by instilling doubt in our customers, thanks.