>Some strange things happened. We suspect that user from time to time copy all files to some place, do some action, print report and then copy back all files, of course without saved action. Idea is to save all his work to some place where he does not have access and later review his actions.

I've seen worse... once upon a time (when I was doing Cobol in STOUR "Banat"), one of the member companies (Gvožđar) required a report on nivelation (you know what's that - and for lurkers out there, that's the inflation report, i.e. how much has our stock gained or lost value due to price changes) where there'd be a running total on the bottom of each page. Note the difference: not the page total, but a running total.

Why? Because their shops were selling stuff at old price to their friends, so the effect of nivelation were often negative. I've seen (seen? printed!) nice examples of that - the price of something would go from 19 something (millions, AFAIR) in February, to 24 in March, to 28 in May, to 32 in June, and then in July one would be sold for 21. The shop boss would probably split the difference with the customer - we never knew.

And the management didn't care. They just wanted the report to show they were not in the red with this. The report ran for maybe forty pages, and they'd just look for a nice number at the bottom, tear off the remaining pages and present that as the final amount. They didn't actually notice that the number on the last page looked even better... they just wanted a report where the total would be close to what they wanted to show.

Your users seem to be more technically advanced... well, it's been 18 years since, so they should :).