If you accept forum accounts as collateral then there is almost a guarantee that every account that you accept will end up needing to be sold by you because the borrower will default.
Based on how many people are selling their accounts via loans, I would not suggest accepting them as collateral
What does it matter if they do default? As long as the amount loaned out is less than what the account is worth then it's all good. Accounts can be perfect collateral really and the lender can actually make a nice return if they do default usually.
It is very difficult to know with certainty that an account has a certain value so the chances are greater that you might lend more the what you can sell it for. There is also the risk that the account was recently involved in a scam that will cause them to get negative trust, rendering it nearly worthless.
If you want to be able to buy up accounts on a cheap basis then it would be better to open a [WTB] thread in digital goods, then at least that way you won't be forced to wait two weeks (or however long the loan is for) to be able to either sell or start using the account.
There is also the issue that by buying accounts via loans that it will be public that an account is sold which decreases its value and lowering your potential return.
Lastly, many lenders do not appear to truly understand that accepting an account as collateral is almost a guarantee that they will end up defaulting as they hear the term "collateral" and they think borrowers have a strong incentive to repay when they do not.
