The reports are that JP Morgan suspected some MFGlobal funds it received were customer deposits.
…”But JPMorgan was not satisfied. The bank once again contacted Mr. Corzine, this time requesting a guarantee in writing.”…..[DealBook article 12/21/11]
JP Morgan asked several times for a letter because they suspected, that MF Global was sending customer money. If a MF Global customer files a civil theft lawsuit (in Florida a win gets double the theft) or a FINRA arbitration claim....JP Morgan may have to payout.
It gets worse...maybe fraud or RICO.........two actors, with knowledge, acting to advance a criminal enterprise....conspiracy (punitive damages)...RICO (more than one MF Global customer's money was removed from segregated funds)?
Take a look at possession of stolen property statutes. (Best place? Look online for jury instructions on possession of stolen property). lawyers can argue that JP Morgan suspected that the funds were from segregated customer accounts. JP Morgan can be a target for a FINRA claim, civil theft suit ( remember the NYT article about a single mother in Fort Lauderdale) or a class action by customers with deposited funds at MF Global.