The first company to release ASICs to end-users was Avalon. Check this out:
http://www.coindesk.com/avalon-accused-of-mining-with-customer-asics/And they blatantly lied to their customers and were quoted as saying they would never mine with customer's hardware.
BFL was the first company to take pre-orders and in their current class-action lawsuit they have admitted to mining for profit with customer's hardware even though BFL promised it would use a test-net.
I would assume every company is cheating unless you know them personally. Sad state of affairs

they'll mine it for some profits
well, profits from selling hardware isnt a good choice for this kind of company, why?
they have to keep up with the new generation, new idea, etc. which will cost them MONEY!
so, its still normal if they mine using customer's hardware...
nvm, cant blame them, they're trying to deliver the best to us