Even as companies use more and more computers, they still need paper. Even if documents are transmitted over the Internet, they are often printed if they need to be studied or signed. That means trade secrets or important internal information may accidentally leak out. One's daily trash bags and recycling bins can be a dumpster diver's treasure trove of details about new ventures, future plans and legal matters. If you destroy your own records, you buy or rent one or more shredders and install them in your office.
Employees simply use the machines at their convenience.
If you hire a service, your company usually gets one or more secure containers for disposing confidential materials. They can be used like recycling bins by simply tossing documents inside. The containers are usually securely locked to keep out interlopers. When destruction day comes, workers either come and haul away your documents or destroy them on-site before witnesses. If they are taken to their site, they should be shredded within a certain length of time, such as 12-24 hours.