Sometimes though the outsourcing does happen within the country.
One solution which is frequently employed (some people might say "abused") to cut salaries is to engage an outsourcing company which takes over the business process and provides domestic personnel to perform the job requirements.
There is nothing wrong with that practice on the surface. What makes it problematic is that the main users of H1-B visas are companies which provide consulting services which are priced cheaper than what corporations pay their own workers. Effectively the companies are building a workforce using H1-B workers to provide the same service cheaper than what it would cost the US corporation to get the job done with In House staff.
The H1-B program does not allow the loss of jobs (substitution) to a H1-B worker. Unfortunately though there is no safeguard to prevent the contractor who takes over the process to use H1-B workers.
The above is apparently exactly what McDonalds did...they hired a company in an attempt to save on their accounting costs. The company who took the job staffed the position with H1-B workers.
Article can be found here
The graphic below shows the Top 19 users of H1-B visa users in the US.
