John Dizard writes:
Capital controls turn into trade controls, as the locals attempt to find ways to turn hard assets or non-banking services into foreign exchange. At some price, for example, you can buy a boat in Cyprus with post-haircut, capital-controlled local deposits, sail it to Lebanon, and then sell it for real, usable money. The same with antiques, jewellery, or anything else you can think of. Even capital goods such as fork lifts can be motored off in the middle of the night.
Here is a long Cardiff Garcia post on capital controls, excellent throughout. From Garcia, there is also this:
Reinhardt, Rogoff and Maduff did a meta-analysis in 2011 on prior studies of capital controls. The only uncontroversially (though mildly) successful use of controls on outflows they found was Malaysia in the aftermath of the Asian financial crisis. Even then, the controls were accompanied by aggressive counter-cyclical spending, bans on short-selling the currency and trading it offshore, and defending the ringgit against speculators by fixing it to the dollar.