A person's reputation is not what is in their signature line . . . Having a paid signature is nothing more then receiving money for advertising a good or a service . . .
The only thing that these people are saying, by accepting to rent their signature space, is that they need the money. Nothing else.
. . . They are simply "wearing" their signature in exchange for payment . . . This is also a very similar arrangement as to how newspapers and TV stations make their money....via advertisements, I would say that common sense would dictate that advertisements are not endorsed by these channels of information
EDIT: unless you personally endorse something you are not "signing" your messages with a specific advertiser
Would any of you have a problem with someone advertising a pedophile website in their signature space? Would you be willing to accept a payment from a pedophile website in exchange for advertising their website in
your signature space?
How about a "murder for hire" business? Would you be willing to accept a payment from a "murder for hire" business in exchange for advertising the business in
your signature?
Most moral and ethical people would refuse to use their own activity to assist businesses that they feel are immoral or unethical. Your decision to accept a payment in exchange for assisting a business says something about yourself and your opinion of the business.
You are essentially agreeing to become a paid employee of the business (you are getting paid, and you are doing work for them). As such, you are intertwining your reputation with that of the business. If you act in immoral and unethical ways, people will hold the business accountable for choosing to pay you and choosing to allow you to represent them. If the business acts in immoral and unethical ways, people will hold you accountable for choosing to provide services for the business and for accepting their "dirty money".
You cannot treat a Ponzi scheme to pedophilia or murder for hire, that's an abusive analogy