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Some people deal with confidential files and use Dropbox for these. It would be very useful to allow people the option to clear their "Recent" files at will to allow more privacy and discretion.
Agree with all on this thread. This lack of security will be the biggest(but not the only) Dropbox "function" that causes me to store my files elsewhere and cancel this service. The right pane and it's crushing effect on file previews is the second largest issue, as it makes the preview function essentially unusable.