You expect confidentiality. The war time saying of loose lips sink ships is very relevant in today's business environment. Here are a few stories.
Misinformation can be damaging to competitors - A while ago, we had recruited a senior accounting and software staff member. We had advertising publicly and this person responded to the advertisement. We subsequently hired her. It turns out she was critical staff member for a competitor. I found this out at an industry conference where I sat down with a few of my team for lunch. It was a shared table. The conversation of the other people on the table was in full flight so it would have impolite to interupt. You guessed it.... they were talking about loosing their staff member to our company. They were discussing confidential things about their company and then saying many things about our company. All of the 'facts' about our company, revenues, staff, client base and more were wrong. It was great that our team were quiet. I was very tempted to correct them, but I was glad I did not. It was better that the competitors did not have a clue about our business.
Discussions with a vendor - Be careful about the amount of information you share with a vendor. I have been in many meetings where vendors are trying to sell me services and provide me with information on my competitors. In many instances, the vendors are not even aware they are doing it. They do not understand enough about my business and are trying to sell their solution.
Your off site staff will be very conscious of protocol - You set the expectations on confidentiality and your off-site staff will follow the rules.