For as long as there's no complaint from the one or the other, there's no harm done. And if there is a complaint, then a judge would be asked to see if there's any possible and serious confusion between the two – not just based on their logo, but on their activities, positions and reputations in their respective markets.
But it seems to me that neither of these scenarios is currently at hand.
Oorspronkelijk geplaatst op Quora: Quicken and Quora use a very similar Q design in their logos. Are companies OK with this when it happens?"