Apple opened its Mac App Store yesterday, offering Mac users an easy way to pick up and install new software on up to five machines — but within hours hackers began claiming to have hacked store security.

The crack will not be available until February 2011, according to Hackulous member, Dissident: It will enable software downloaded from the store to be installed on more Macs.

We’ll see how this pans out — we’d anticipate Apple and its developers will be infuriated that their already liberal approach to install rights (up to five Macs) may have been thwarted.

Most of the applications that go on the Mac App Store [in the first instance] will be decent, they’ll be pretty good. Apple isn’t going to put crap on the App Store as soon as it gets released. It’ll probably take months for the App Store to actually have a bunch of crappy applications and when we feel that it has a lot of crap in it, we’ll probably release Kickback.

So we’re not going to release Kickback until well after the store’s been established, well after developers have gotten their applications up. We don’t want to devalue applications and frustrate developers.”