Dear Annie: I read your column on whether (or when) non-compete agreements are negotiable, but I have a much weirder question. I just got a great job offer from a company where I've always wanted to work, but one thing is giving me pause. The HR people haven't asked me to sign a non-compete, exactly, but they do want me to sign something they're calling an "assignment agreement," which basically says the company owns the rights to all my ideas or inventions, both now and in the future.

    This makes me nervous because, for the past five or six years, I've been developing something in my spare time that I think has great commercial potential, and I'm getting close to applying for a patent. Does this agreement mean my employer owns my invention, even though it has nothing to do with my job? That just seems bizarre. Or am I reading this wrong? -- Lost in Los Gatos

    Dear L.L.G.: I'm sorry to report that you're probably reading it just fine. Assignment contracts, also called preassignment agreements, are often buried in dense thickets of legalese in non-compete contracts, but since non-competes are illegal in California, you've been presented with the stand-alone version. Typically, it means you're signing over the entire contents of your brain to your employer.

    More and more new hires are being asked to sign these contracts "across all industries and in all kinds of jobs," notes Orly Lobel, a law professor at the University of San Diego and cofounder of its Center for Intellectual Property Law and Markets. She also wrote a new book you might want to check out, called Talent Wants to Be Free: Why We Should Learn to Love Leaks, Raids, and Free Riding.

    "Assignment agreements used to be mostly confined to people specifically hired to create or invent, but not anymore," Lobel says. These days, "the trend is toward companies trying to control all creativity, including skills, ideas, discoveries, and techniques -- tacit knowledge that isn't subject to patent or copyright under the traditional scope of the law."

    The worst part, from your point of view, is that these contracts often stretch into the indefinite future. "Many of them contain a 'trailer clause,' which essentially means, 'Even if you invent something years after you leave here, we will own it anyway,'" Lobel says.

    Outlandish as that seems, the agreements have teeth. Talent Wants to Be Free goes into some detail about what Lobel calls "strategic litigation," where companies have sued former employees, especially those who quit to start their own businesses. Such lawsuits can be enough to kill a new company. "Even the threat of litigation is a big red flag to investors," Lobel notes. "Venture capitalists won't come near you."

    Your situation does have one bright spot: You live in California. Along with several other states -- including Delaware, Illinois, Kansas, Minnesota, Washington, and North Carolina -- the Golden State has passed laws putting a few limits on employers' right to claim ownership of employees' brainpower.

    In particular, California courts have relied on the same statutes that ban non-compete agreements to overturn assignment contracts considered too restrictive or far-reaching. Not only that, but state law says that, as long as you developed your invention in your spare time and without using any of your employer's resources or proprietary information, your assignment agreement -- including any trailer clauses -- can't be enforced. (And yes, your employer no doubt knows that, but may be hoping that you don't.)