These are the minority; the small, tiny, miniscule minority. And the reason I don't worry about them and don't devise my company policies around them is because you operate from a position of weakness rather than strength when you do this.
To explain, people (and companies) who operate like this will always exist. But, why build your company policy around those when the vast majority don't?
Most freelance writers are honest, hardworking and loyal. They are so happy to be getting work from you that they'd never jeopardize this relationship by going behind your back and stealing your clients. And you know why?
Because the client may not go for it . . . and inform you of the freelance writer's attempt to lure them away as a client. And, I've found that most clients act the same way. They wouldn't dream of "hiring a freelance writer away from you." Why?
Because if a client is happy with you - ie, you provide quality content, at a reasonable rate, and it's always on time - they don't want to upset the apple cart. So, they'd never betray you by going with one of your freelancers.
Freelance Writing Independent Contractor's Agreement
Every once in a while, a client will ask me to sign an NDA (Non-Disclosure Agreement). This is akin to an outsource agreement a freelance writing firm would have with any freelancers they hire. If you're worried about this, you can have one of these.
It's a freelance writing contract and confidentiality agreement -- all rolled into one. It's in Word and is fully customizable - all you have to di is insert your company's name in the designated areas.
Why I Don't Use a Freelance Writing Agreement/Contract
With the vast majority of my clients, I don't use a freelance writing agreement. To protect my behind in case of having to take legal action (which I've never done in almost 20 years of being a freelance writer), I keep all correspondence relating to a project.
In emails, rate and other projects specifics are usually discussed. If you ever have to enter a court of law, these will suffice.
HOWEVER, the few instances I do use a Freelance Writing Agreement/Contract (http://bit.ly/cK8zOR) have to do with who owns the rights to the work (eg, my firm or the client).
Although my company policy spells out that clients own it as it relates to their project, just so there are not gray areas, if my gut tells me that a client may be a problem or that there's a "fuzzy" area, I put one in place.
And, sometimes the client will ask you to sign theirs - which I usually do with no hesitation (after reading through the agreement in its entirety).
Should You Get Legal Help to Understand Freelance Writing Contracts/Agreements?
FYI, I worked for a legal publishing firm for 10 years, so am readily familiar with the legal jargon included in most contracts. If you're not, get a friend or loved one with some experience in this area to guide you through this - or consult an attorney.
I hope this helps you to understand more about the intricacies of hiring freelance writers to outsource to - while protecting your client base.