Next time, hopefully you'll watch as he systematically adds leads and contacts to your company's Salesforce account. You can't control what knowledge he gains o

Next time, hopefully you'll watch as he systematically adds leads and contacts to your company's Salesforce account. You can't control what knowledge he gains on the job, but you can establish proper procedures for recording on-the-job data which could include a prohibition on recording that data into personally owned systems, perhaps through trade secrets claims. Thus, future employees are free to take themselves and their knowledge to their next employment but (enforeceability issues aside) they can't take the company's data.