Look at their true motivation behind the PIP. If it is discriminatory in nature or retaliation for your complaints of illegalities, then you will have much greater legal rights and should see an attorney.
However, if it really is based on your performance, and the goals are just not as clear as you would desire, play their game and sign it, especially if you are only acknowledging receipt and not agreement with all the accusations. Otherwise they could write you up for being insubordinate.
If they say you can't correct it, then don't, but submit a separate letter expressing your concerns or asking for clarification so you can achieve definable goals. Don't wait for the PIP period to expire to find out how you are doing. But rather asked for a week by week review so you will know you are on track.
The prior answer is correct. However, the laws in California where that attorney practices is vastly different from those in Georgia. If you don't sign the PIP, they can fire you, but you can note your objection in detail (in writing on that document or a separate document) .
The problem is that Georgia is a "right to work" state. Of course, this description is misleading. In reality, the employer has the right to fire you for any reason, even a stupid one.
Nevertheless, if you believe discrimination is behind the PIP, visit the EEOC's website. www.EEOC.gov to learn more about your rights.
At this point in time, all you can do is submit a response demonstrating why the PIP is based on erroneous information. If you have to take legal actioin later, you will want to analyze the circumstances to determine whether you have a potential legal claim. Being able to sue an employer for wrongful termination usually involves more than simply being able to prove that you did not do anything wrong. Wrongful termination is a generic term that refers to any termination that can result in legal action against the employer. Although the laws are different from state to state, generally there are several different types or varieties of wrongful termination claims. Your rights as an employee depend on several things. One, whether you have a contract of employment and, if so, whether the employer violated the contract. Two, whether you are in a union, and if so, whether the union agreement was violated by the employer. Three, whether you are a government or civil service employee protected by civil service or other government laws or regulations, and, if so, whether the employer violated those laws or regulations. And four, in addition to the above (or if none of the above apply and you are an at will employee), whether the employer had some legally prohibited motive or reason for the termination. Most of the illegal or improper reasons for termination are exceptions to the at will doctrine and they require proof of some illegal or improper motive such as discrimination due to your age, race, sex, color, national origin, pregnancy or disability. Some exceptions require proof of a retaliatory motive such as retaliation for complaining about illegal conduct of the employer like not paying overtime, or violating OSHA regulations, or discrimination, or taking FMLA leave, or filing a workers comp claim, or doing other things that the law either gives you a specific right to do or imposes an obligation to do.
If you want to determine if your rights have been violated as an employee your best course of action is to speak to an employment lawyer and be prepared to discuss the possible motives for the adverse employment action. The question of how long you have to file a claim depends on which one of the possible claims you may have.
Disclaimer: This answer is provided as a public service and as a general response to a general question, it is not meant, and should not be relied upon as specific legal advice, nor does it create an attorney-client relationship.