diff --git a/examples/Makefile.am b/examples/Makefile.am
index 7b51e90..0fb6571 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -1,4 +1,4 @@
-AM_CFLAGS = -I. @LIBNFC_CFLAGS@
+AM_CFLAGS = -I. -I$(top_builddir)/libfreefare @LIBNFC_CFLAGS@
 AM_LDFLAGS = @LIBNFC_LIBS@
 
 bin_PROGRAMS = mifare-classic-format
diff --git a/examples/mifare-classic-format.c b/examples/mifare-classic-format.c
index 689e96b..5f6d46b 100644
--- a/examples/mifare-classic-format.c
+++ b/examples/mifare-classic-format.c
@@ -1,200 +1,99 @@
+#include <err.h>
+#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
-#include <err.h>
 
 #include <nfc/nfc.h>
 
 #include <freefare.h>
 
-#define DEBUG
+#define block_address(sector, block) ((sector * 4) + block)
 
-// Useful macros
-#ifdef DEBUG
-//   #define DBG(x, args...) printf("DBG %s:%d: " x "\n", __FILE__, __LINE__,## args )
-  #define DBG(x, ...) fprintf(stderr, "DBG %s:%d: " x "\n", __FILE__, __LINE__, ## __VA_ARGS__ )
-#else
-  #define DBG(...) do {} while (0)
-#endif
-
-static nfc_device_t *device = NULL;
-static MifareClassicTag *tags = NULL;
+MifareClassicKey default_keys[] = {
+    { 0xff,0xff,0xff,0xff,0xff,0xff },
+    { 0xd3,0xf7,0xd3,0xf7,0xd3,0xf7 },
+    { 0xa0,0xa1,0xa2,0xa3,0xa4,0xa5 },
+    { 0xb0,0xb1,0xb2,0xb3,0xb4,0xb5 },
+    { 0x4d,0x3a,0x99,0xc3,0x51,0xdd },
+    { 0x1a,0x98,0x2c,0x7e,0x45,0x9a },
+    { 0xaa,0xbb,0xcc,0xdd,0xee,0xff },
+    { 0x00,0x00,0x00,0x00,0x00,0x00 }
+};
 
 int
-mifare_classic_setup (MifareClassicTag *tag)
+try_format_sector (MifareClassicTag tag, MifareSectorNumber sector)
 {
-    int res = 0;
+    for (int i = 0; i < (sizeof (default_keys) / sizeof (MifareClassicKey)); i++) {
+	printf (" s=%d i=%d \n", sector, i);
+	if ((0 == mifare_classic_connect (tag)) && (0 == mifare_classic_authenticate (tag, block_address (sector, 0), default_keys[i], MFC_KEY_A))) {
+	    if (0 == mifare_classic_format_sector (tag, sector)) {
+		mifare_classic_disconnect (tag);
+		return 0;
+	    } else if (EIO == errno) {
+		err (EXIT_FAILURE, "sector %d", sector);
+	    }
+	    mifare_classic_disconnect (tag);
+	}
 
-    *tag = NULL;
+	if ((0 == mifare_classic_connect (tag)) && (0 == mifare_classic_authenticate (tag, block_address (sector, 0), default_keys[i], MFC_KEY_B))) {
+	    if (0 == mifare_classic_format_sector (tag, sector)) {
+		mifare_classic_disconnect (tag);
+		return 0;
+	    } else if (EIO == errno) {
+		err (EXIT_FAILURE, "sector %d", sector);
+	    }
+	    mifare_classic_disconnect (tag);
+	}
+    }
+
+    return -1;
+}
+
+int
+main(int argc, char *argv[])
+{
+    int error = 0;
+    nfc_device_t *device = NULL;
+    MifareClassicTag *tags = NULL;
+    MifareClassicTag *tag = NULL;
 
     device = nfc_connect (NULL);
     if (!device)
-	res = -1;
+	errx (EXIT_FAILURE, "No NFC device found.");
 
-    if (0 == res) {
-	tags = mifare_classic_get_tags (device);
-	if (!tags) {
-	    nfc_disconnect (device);
-	    device = NULL;
-	    res = -2;
+    tags = mifare_classic_get_tags (device);
+    if (!tags) {
+	nfc_disconnect (device);
+	errx (EXIT_FAILURE, "Error listing MIFARE classic tag.");
+    }
+
+    if (!tags[0]) {
+	mifare_classic_free_tags (tags);
+	nfc_disconnect (device);
+	errx (EXIT_FAILURE, "No MIFARE classic tag on NFC device.");
+    }
+
+    tag = tags;
+
+    while (*tag) {
+	char *tag_uid = mifare_classic_get_uid (*tag);
+
+	/* FIXME get the tag size */
+	size_t sector_count = 15;
+
+	for (size_t n = 0; n < sector_count; n++) {
+	    if (try_format_sector (*tag, n) < 0) {
+		warnx ("%s: Can't format sector %d (0x%02x)", tag_uid,  n, n);
+		error = 1;
+	    }
 	}
+
+	free(tag_uid);
+	tag++;
     }
 
-    if (0 == res) {
-	if (!tags[0]) {
-	    mifare_classic_free_tags (tags);
-	    tags = NULL;
-	    nfc_disconnect (device);
-	    device = NULL;
-	    res = -4;
-	}
-    }
+    mifare_classic_free_tags (tags);
+    nfc_disconnect (device);
 
-    if (0 == res) {
-	*tag = tags[0];
-
-	res = mifare_classic_connect (*tag);
-	if (res != 0) {
-	    mifare_classic_disconnect (*tag);
-	    nfc_disconnect (device);
-	    *tag = NULL;
-	    device = NULL;
-	    res = -3;
-	}
-    }
-
-    return res;
+    exit (error);
 }
-
-int
-mifare_classic_teardown (MifareClassicTag tag)
-{
-    int res;
-
-    if (tag)
-	res = mifare_classic_disconnect (tag);
-
-    if (0 == res) {
-	if (tags)
-	    mifare_classic_free_tags (tags);
-
-	if (device)
-	    nfc_disconnect (device);
-    }
-
-    return res;
-}
-
-void 
-print_block(MifareClassicBlock *data)
-{
-    for(size_t n=0;n<sizeof(MifareClassicBlock);n++) {
-        printf("0x%02x ", (*data)[n]);
-    }
-}
-
-#define block(s,b) ((s * 4) + b)
-bool 
-sector_is_empty(MifareClassicTag tag, MifareSectorNumber sector)
-{
-    MifareClassicKey default_key = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
-
-    if( 0 != mifare_classic_authenticate(tag, block(sector, 0), default_key, MFC_KEY_A) ) {
-        mifare_classic_connect(tag);
-        DBG("%s", "Unable to authenticate using default key A.");
-        return false;
-    }
-
-    MifareClassicBlock default_block = {
-        0x00, 0x00, 0x00, 0x00, 
-        0x00, 0x00, 0x00, 0x00, 
-        0x00, 0x00, 0x00, 0x00, 
-        0x00, 0x00, 0x00, 0x00, 
-    };
-    MifareClassicBlock block;
-    if( 0 != mifare_classic_read(tag, block(sector, 1), &block) ) {
-        DBG("Unable to read block %d of sector %d (%02x).", 1, sector, block(sector, 1));
-        return false;
-    }
-
-    if( 0 != memcmp( &block, &default_block, sizeof(MifareClassicBlock))) {
-        DBG("Block %d of sector %d (%02x) doesn't match with default data.", 1, sector, block(sector, 1));
-        return false;
-    }
-
-    if( 0 != mifare_classic_read(tag, block(sector, 2), &block) ) {
-        DBG("Unable to read block %d of sector %d (%02x).", 2, sector, block(sector, 2));
-        return false;
-    }
-
-    if( 0 != memcmp( &block, &default_block, sizeof(MifareClassicBlock))) {
-        DBG("Block %d of sector %d (%02x) doesn't match with default data.", 2, sector, block(sector, 2));
-        return false;
-    }
-
-    if( 0 != mifare_classic_read(tag, block(sector, 3), &block) ) {
-        DBG("Unable to read block %d of sector %d (%02x).", 3, sector, block(sector, 3));
-        return false;
-    }
-
-    MifareClassicBlock default_trailer_block = {
-        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* Key A could not be read */
-        0xff, 0x07, 0x80, /* Default access bits */
-        0x69, /* Default GPB */
-        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* Default Key B */
-    };
-    if( 0 != memcmp( &block, &default_trailer_block, sizeof(MifareClassicBlock))) {
-        DBG("Block %d of sector %d (%02x) doesn't match with default data.", 3, sector, block(sector, 3));
-        printf("attemped data = "); print_block(&default_trailer_block); printf("\n");
-        printf("tag data = "); print_block(&block); printf("\n");
-        return false;
-    }
-    return true;
-}
-
-int main(int argc, char *argv[])
-{
-    MifareClassicTag tag;
-    if( 0 == mifare_classic_setup(&tag) ) {
-        for(MifareSectorNumber s = 0; s < 16; s++) {
-            printf("Sector %d is %s empty.\n", s, sector_is_empty(tag, s) ? "" : "_not_");
-        }
-
-#if 0
-    MifareClassicKey key_b = { 0xd3, 0xf7, 0xd3, 0xf7, 0xd3, 0xf7 };
-/*
-    if( 0 != mifare_classic_authenticate(tag, 0x04, key_b, MFC_KEY_B) ) {
-       errx(1, "Unable to authenticate.");
-    }
-    mifare_classic_format_sector(tag, 0x04);
-    if( 0 != mifare_classic_authenticate(tag, 0x08, key_b, MFC_KEY_B) ) {
-       errx(1, "Unable to authenticate.");
-    }
-    mifare_classic_format_sector(tag, 0x08);
-*/
-    if( 0 != mifare_classic_authenticate(tag, 0x08 + 4, key_b, MFC_KEY_B) ) {
-       errx(1, "Unable to authenticate.");
-    }
-    mifare_classic_format_sector(tag, 0x08 + 4);
-
-/*
-    if( 0 != mifare_classic_authenticate(tag, 0x00, key_b, MFC_KEY_B) ) {
-       errx(1, "Unable to authenticate.");
-    }
-
-    if( 0 != mifare_classic_write(tag, 0x01, empty) )
-      errx(1, "Unable to write on block @0x01");
-    if( 0 != mifare_classic_write(tag, 0x02, empty) )
-      errx(1, "Unable to write on block @0x02");
-
-    if( 0 != mifare_classic_write(tag, 0x03, trailer) )
-      errx(1, "Unable to write trailer block");
-*/
-#endif
-
-    mifare_classic_teardown(tag);
-    exit(EXIT_SUCCESS);
-  } else {
-    errx(1, "Unable to connect to a MIFARE Classic tag.");
-  }
-}
-