Very interesting.  Well, the technical information makes it reasonable enough to accept what you've said as valid.  I apologize sincerely for jumping to conclusions about you, dropboxexpander.

Freelancer.com's Data Entry listings are so full of job postings that end up being Dropbox scams, that applying for data entry positions is a lost cause.  Typical Dropbox postings advertise data entry positions, and often emphasize that they're willing to hire people who've had no prior data entry jobs.  30 - 40 job candidates respond with their interest.  Those candidates are PM'ed by the job poster, telling them that there's a few things they'll need to do to get started.  First, they're directed to an online typing test that takes about three minutes.  They're told to send a JPG of their typing speed results.  They're also given a shortened referral link to Dropbox and told to create an account there "to receive work files", and PM the "employer" with the e-mail address they used to register at Dropbox.

Reading the list of applicant replies, these postings get a lot of responses.  Each.  The entire lot of applicants is then kicked to the curb as the job posting is cancelled, and the process repeats: New "employer" account purporting to be from somewhere else, new user image (I got a nice Middle Eastern lady named "Dr. Munni"), same body text verbatim.  I was out for a data entry job, noticed this, and got suspicious.  That's when I checked Dropbox and found out they were offering free drivespace for referrals.

I've contacted Freelancer.com and Dropbox about it, but there's little they can do without getting together to share IP log information.  And even that isn't likely to do much if scammers are using proxies.  I suppose if Dropbox has been notified of this and keeps their offer without providing due diligence, they're liable to a class action from sites and job seekers for knowingly enabling the problem.

That's all the info I have on this.