I'm not sure if "the Bitcoins are still mine" is an appropriate interpretation - (just as with banks) you don't own those particular BTC that you deposited, these now belong to Coinbase, what you have is a claim, a debt, an IOU, a statement from Coinbase that they'll give you a particular amount BTC on demand. If the standard banking regulations apply (and why wouldn't they? Coinbase is licenced as a money transmitter) there are no any particular "named" BTC held in escrow particularly for you, there's an "account" that tallies how much BTC you "have", i.e., how much BTC Coinbase owes you - as their user agreement states, "you are the owner of the balance of each of your Currency Wallets".
In the absence of any specific agreements with Coinbase regarding usufruct rights, you wouldn't have them (just as you don't have usufruct rights when depositing currency in a bank account) - you don't own that BTC, Coinbase owes you some fixed amount of BTC, and that's that.
Of course, that would be a nice thing to test in courts - after all they decide who owes what to whom, not the algorithms of BTC/BCC.
In the absence of any specific agreements with Coinbase regarding usufruct rights, you wouldn't have them (just as you don't have usufruct rights when depositing currency in a bank account) - you don't own that BTC, Coinbase owes you some fixed amount of BTC, and that's that.
Of course, that would be a nice thing to test in courts - after all they decide who owes what to whom, not the algorithms of BTC/BCC.