How to detect a cracked iPhone App and a jailbroken device (different methods)

Question

I\'m building a blacklisting service for cracked iPhone apps and I am curious if I missed a method for detecting cracked apps.

In the moment following app crack detectio

Answer 1

NEVER try and block jailbroken devices from using your app, just cracked ones. If you block jailbroken devices they'll be forced to use a patched version with all the checks removed.
Also ALL my devices are jailbroken so if a developer blocks jailbroken devices I would have to ignore their apps. Over 10% of all iDevices are jailbroken so this is a very bad idea.

EDIT: As I'm getting lots of down votes for this I'll post some methods to detect a jailbreak.

- (BOOL)fileExistsAtPath:(NSString *)path{
    NSLog(@"Check if file '%@' exists", path);

    struct stat buffer;   
    return stat([path UTF8String], &buffer) == 0;
}

- (BOOL)jailbroken{
    return ([self fileExistsAtPath:@"/Applications/Cydia.app"]);
}

Answer 2

-(IBAction)rootCheck:(id)sender {

    NSArray *jailbrokenPath = [NSArray arrayWithObjects:
                               @"/Applications/Cydia.app",
                               @"/Applications/RockApp.app",
                               @"/Applications/Icy.app",
                               @"/usr/sbin/sshd",
                               @"/usr/bin/sshd",
                               @"/usr/libexec/sftp-server",
                               @"/Applications/WinterBoard.app",
                               @"/Applications/SBSettings.app",
                               @"/Applications/MxTube.app",
                               @"/Applications/IntelliScreen.app",
                               @"/Library/MobileSubstrate/DynamicLibraries/Veency.plist",
                               @"/Applications/FakeCarrier.app",
                               @"/Library/MobileSubstrate/DynamicLibraries/LiveClock.plist",
                               @"/private/var/lib/apt",
                               @"/Applications/blackra1n.app",
                               @"/private/var/stash",
                               @"/private/var/mobile/Library/SBSettings/Themes",
                               @"/System/Library/LaunchDaemons/com.ikey.bbot.plist",
                               @"/System/Library/LaunchDaemons/com.saurik.Cydia.Startup.plist",
                               @"/private/var/tmp/cydia.log",
                               @"/private/var/lib/cydia", nil];

    NSString *rooted;
    for(NSString *string in jailbrokenPath)
        if ([[NSFileManager defaultManager] fileExistsAtPath:string])
            rooted=@"y";
        else
            rooted=@"n";

    NSLog(@"%@", rooted);
}

sample code: http://www.evernote.com/shard/s13/sh/e45f27ee-3dd5-4eb1-9f56-1981cdd3286b/bc156eb773315647c13c2c7ee4191866