Pro: Caller ID gives recipients the ability to screen their calls, that is, to determine beforehand whether they want to talk with a particular caller.
Pro: Caller ID provides a deterrent to the harassment of some telephone customers by others. Those who would make obscene or threatening phone calls could be more easily discovered, and so they would be less likely to make such calls.
Pro: Caller ID enables some businesses to improve services to their customers. Those companies that require customers to identify themselves before information can be exchanged or orders can be sent would have a means by which a verification of the identities of callers could be made.
Con: Since neither public agencies nor private businesses have the right to discriminate in their communications with citizens, they should not have access to the technology that enables them to discriminate. With the availability of caller ID, some regions may be unjustly denied various benefits: for example, food delivery and taxi services may choose not to respond to calls that originate in certain areas.
Con: If caller ID is permitted, some businesses that depend on making 'cold calls' to potential customers will suffer a loss of revenue: All telemarketers will suffer a reduction in the sales they generate; some telemarketers will be put out of business.
Con: Caller ID may put some people at risk of being harmed by others. Those who do not wish to reveal their locations for fear of suffering reprisals may not be able to conceal their whereabouts.
Reply: The technology allows users to keep their identities secret: in place of the number of the caller, the recipient sees only the word 'Restricted'.