Would you apply to a job ad if the employer does not identify themselves?

[kilaj1]

Resumes effectively not private.

Given the nature of how job seeking is going now, if you post your resume online at hotjobs.com, monster.com and many other online Job Sites. Those resumes are made available to employers who pay to access them.

A large number of employers, WHO YOU DO NOT KNOW, are able to search and review your resume and you never know.

True but you have an option in most of these sites to turn that feature off and on some restrict who can view your resume, namely Unknown companies. I've done it with my workopolist account.

The fact you can find out the company that the fax or telephone number belongs does not mean that it is that company that is recruiting. IT might actually be a related company or a subsidiary.

Some companies ask other companies to collection the applications for them and then pass it on.

True again but look at the example above, what are the chances that that company is a third party recruitment company? Knowing some info is better than knowing none.