[aneth4]

Tried them. It says:

"Sorry, the maximum number of purchases on Coinbase has been reached for today. Please try again in 24 hours. We'll continue raising this limit over time."

These sort of security and reliability concerns are certain to hold bitcoin back. Granted they also represent the opportunity, as surely they will be resolved.

[ok_craig]

Well there's always MtGox, which I don't think has any limits, but you have to give them an absurd amount of identity verification to be able to place orders, which scared me away.

There are multiple services, Coinbase is just one of them. This particular instance of you not being able to place an order through them is not indicative of a wider tendency to not be able to place orders.

Coinbase has a 24-hour rolling limit for how many coins can be sold through them. This is reliably the case every day.

Also, not being able to buy coins doesn't seem to be a "security" issue.