Businesses both large and small often have specific rules and regulations regarding what their employees may or may not do while using a company computer. Internet usage agreements are common; many employers require employees to sign Internet usage agreements before they can begin work. There may be specific guidelines regarding the use of certain online programs, and personal email may in some cases be disallowed while using a company computer. It is up to the individual employer to decide and implement the guidelines of an Internet usage agreement. Some employers may choose not to use an agreement, allowing their employees the freedom to use their computers as they see fit. Other employers may block certain websites or programs, or block access to the Internet completely on company computers. Still other employers may choose to use computer monitoring programs to snoop on their employees Internet activity, and they are usually legally allowed to do so.