This letter to the Wichita Eagle, in Kansas (a follow up to their article on BOC here)
demonstrates how at least one consumer views POP as more secure than
BOC. The consumer's rationale is that if the paper check is returned to
them the merchant isn't responsible for safeguarding their personal
data:

Letter to the Editor, Wichita Eagle: 

Scary bank rule

Regarding
"New rule offers 2nd option to electronically convert checks" (May 2
Business & Money): Right now, when huge Wal-Mart or tiny Bionic
Burger electronically converts my paper check to an electronic debit, I
am given the paper check back. I am responsible for that piece of
paper, which has personal information on it.   
 

When a bank handles my paper check, it is responsible for my personal information.   
 

When
a business uses a "Back Office Conversion," who is responsible for my
personal information — including a perfect example of my signature?
Some business, without my knowledge or consent, now has a valuable
piece of paper, which it must dispose of safely. With all the problems
involved in identity theft or check fraud, how does a business protect
its customers' information? The name and address of my bank, my
checking account number, the routing number, and my signature may all
be used without my knowledge to empty my account or disrupt my credit.
Will the businesses using the Back Office Conversion system let their
customers know what they are doing?   

JAMES KEENER

Wichita

One wonders how this consumer feels when they write a check that is NOT converted.