<sod >The people familiar with its investigation said that the company is looking at a set of ads that cost less than $100,000 and that it is still sorting out whether all of the ads came from trolls or whether some originated from legitimate Russian accounts.< eod>< sod > The people familiar with its investigation said that the company is looking at a set of ads that cost less than $100,000 (Â£76,000) and that it is still sorting out whether all of the ads came from trolls, or whether some originated from legitimate Russian accounts.< eod>