In reply to:
As the owner of the site, it's always (in my opinion) required to have all the access over other users.
If you are adamant that ftp is the only way to go with this, then you could setup a crontab in each individual member's account that chown's the upload directory contents to your admin user every so-often, thus giving you full rights.
I think what you're trying to accomplish would be easier to do using php or cgi upload scripts which are linked to each member's folder. For example, member1 logs in and goes to the upload page. Anything he uploads is placed in the ~/domain.com/team/member1/ directory.
In reply to:
It's still *your* car and *you* get to decide who gets to drive it. You don't want your friends deciding who should drive your car.
That's probably the best analogy I've read that clearly explains/justifies ownership within UNIX.
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