Ag-gag laws pose a threat to a wide spectrum of values and issues Americans care about. Because of this, many highly respected national organizations representing a range of public interests, including the ASPCA, have signed a statement  in opposition to ag-gag bills. Read the statement of opposition to proposed ag-gag legislation. 
Social issues potentially impacted by ag-gag laws include, but are not limited to:
Ag-gag laws are a direct threat to animal welfare. We know that animals are often cruelly treated in factory farms and slaughterhouses. Documentation of this treatment not only helps educate the public about farm animal abuse, but also influences industry and government entities to make real changes for farm animals.
Ag-gag laws threaten our food supply: Various exposés of factory farms and slaughterhouses have revealed the extent to which our meat, eggs and milk are mishandled. Mishandling animal products, including mishandling farm animals while they are alive, invites health risks including salmonella, mad cow disease and other potentially fatal illnesses that may be transmitted to consumers.
Control over Food Choices.
Ag-gag laws are a direct threat to marketplace transparency. At a time when Americans are increasingly invested in knowing more about where their food comes from and how it is made, these laws threaten our ability to control what we bring into our homes and the food we put in our bodies. All Americans should have the right to know the basic conditions under which their food is produced.
This legislation often seeks to criminalize the recording of sounds or images in animal facilities, no matter the content. Factory farms, slaughterhouses and meatpacking facilities are physically and emotionally difficult places to work. Farm investigations have the potential to expose serious worker abuse and other illegal or unethical conduct on the part of employees or supervisors.
Some ag-gag bills seek not just to criminalize recording, but even the possession and distribution of images recorded on animal facilities—and some seek to criminalize misrepresenting oneself on job applications (which, while possibly an act warranting termination of employment, should generally not be a crime). These provisions pose serious First Amendment threats.
In the United States, 99 percent of food animals are raised in factory farms, where large numbers of animals are housed together, generally in close confinement. Huge amounts of waste are generated, the improper storage and disposal of which threatens our soil and water. While state and federal laws require large farms to minimize their environmental damage, farms have been found flagrantly violating these requirements. Undercover investigations offer an effective way to expose such violations.
Ag-gag laws are also troublesome because they do not reflect the public's will. Polls consistently show that the majority of Americans favor humane treatment of farm animals. A 2012 poll conducted for ASPCA by Lake Research  revealed that 94 percent of the general American public agrees that "from every step of their lives on a farm—from birth to slaughter—farm animals should be treated in a way that inflicts the least amount of pain and suffering possible." The same poll also revealed that 71 percent of American adults support undercover investigative efforts to expose farm animal abuse on industrial farms, and that 64 percent oppose making such investigations illegal.