added note about bruteforce_keyid creating keys that do not work

README.md

@@ -67,3 +67,35 @@ On my laptop it compares about 12,000 fingerprints per second. Here's how to use
 
     ./bruteforce_keyid [USERID] [KEYID]
 
+*Note: The keys generated by this script are likely cryptographically secure, but sadly they don't seem to actually work to do crypto operations.* For example:
+
+    [user@gpgvm ~]$ gpg --homedir vanity_homedir/ --list-secret-keys 
+    vanity_homedir//secring.gpg
+    ---------------------------
+    sec   4096R/22222222 2014-03-10
+    uid                  Micah Lee <micah@micahflee.com>
+
+    sec   4096R/CCCCCCCC 2014-01-12
+    uid                  Micah Lee <micah@micahflee.com>
+
+    sec   4096R/D15C0FAD 2014-01-26
+    uid                  Micah Lee <micah@micahflee.com>
+
+    sec   4096R/D15EA5ED 2014-02-07
+    uid                  Micah Lee <micah@micahflee.com>
+
+    sec   4096R/FAC701D5 2014-05-01
+    uid                  Micah Lee <micah@micahflee.com>
+
+    sec   4096R/FEE1DEAD 2014-02-08
+    uid                  Micah Lee <micah@micahflee.com>
+
+    sec   4096R/00000001 2013-12-05
+    uid                  Micah Lee <micah@micahflee.com>
+
+    [user@gpgvm ~]$ gpg --homedir vanity_homedir/ --default-key D15EA5ED --detach-sign test 
+    gpg: no default secret key: unusable secret key
+    gpg: signing failed: unusable secret key
+
+If anyone wants to fix this problem, pull requests are welcome.
+