I think the checkpoints are about at least a month or two back in time. Anyone who has more than 51% of 6.5 Petahash of mining power that can fork their own chain past the latest check point, is better off mining regularly and getting 51% of 3600 coins daily or about 1800 coins, at least for the next 2000 blocks when the difficulty will double.
Of course hidden fork crunched at high speed in shadow is unlikely, and maybe checkpoints do not harm due to low probability of such fork.
But they harm in other way - they compromise Bitcoin decentralization, which is in my opinion is the biggest attractive feature of Bitcoin.
Today they add checkpoints (this effectively changes protocol specification), tomorrow they could freeze BTC on your address, by adding small tweaks to validation routine (just like checkpoints validation).
Nonsense, every word.
root@linuxcoin:/home/user# bitcoind --help
Bitcoin version v0.8.6.0-g03a7d67-beta
Usage:
bitcoind [options]
bitcoind [options] [params] Send command to -server or bitcoind
bitcoind [options] help List commands
bitcoind [options] help Get help for a command
Options:
-? This help message
-conf= Specify configuration file (default: bitcoin.conf)
-pid= Specify pid file (default: bitcoind.pid)
-gen Generate coins (default: 0)
-datadir=
Specify data directory
-dbcache= Set database cache size in megabytes (default: 25)
-timeout= Specify connection timeout in milliseconds (default: 5000)
-proxy= Connect through socks proxy
-socks= Select the version of socks proxy to use (4-5, default: 5)
-tor= Use proxy to reach tor hidden services (default: same as -proxy)
-dns Allow DNS lookups for -addnode, -seednode and -connect
-port= Listen for connections on (default: 8333 or testnet: 18333)
-maxconnections= Maintain at most connections to peers (default: 125)
-addnode= Add a node to connect to and attempt to keep the connection open
-connect= Connect only to the specified node(s)
-seednode= Connect to a node to retrieve peer addresses, and disconnect
-externalip= Specify your own public address
-onlynet= Only connect to nodes in network (IPv4, IPv6 or Tor)
-discover Discover own IP address (default: 1 when listening and no -externalip)
-checkpoints Only accept block chain matching built-in checkpoints (default: 1)
-listen Accept connections from outside (default: 1 if no -proxy or -connect)
-bind= Bind to given address and always listen on it. Use [host]:port notation for IPv6
-dnsseed Find peers using DNS lookup (default: 1 unless -connect)
-banscore= Threshold for disconnecting misbehaving peers (default: 100)
-bantime= Number of seconds to keep misbehaving peers from reconnecting (default: 86400)
-maxreceivebuffer= Maximum per-connection receive buffer, *1000 bytes (default: 5000)
-maxsendbuffer= Maximum per-connection send buffer, *1000 bytes (default: 1000)
-paytxfee= Fee per KB to add to transactions you send
-daemon Run in the background as a daemon and accept commands
-testnet Use the test network
-debug Output extra debugging information. Implies all other -debug* options
-debugnet Output extra network debugging information
-logtimestamps Prepend debug output with timestamp (default: 1)
-shrinkdebugfile Shrink debug.log file on client startup (default: 1 when no -debug)
-printtoconsole Send trace/debug info to console instead of debug.log file
-rpcuser= Username for JSON-RPC connections
-rpcpassword= Password for JSON-RPC connections
-rpcport= Listen for JSON-RPC connections on (default: 8332 or testnet: 18332)
-rpcallowip= Allow JSON-RPC connections from specified IP address
-rpcconnect= Send commands to node running on (default: 127.0.0.1)
-rpcthreads= Set the number of threads to service RPC calls (default: 4)
-blocknotify= Execute command when the best block changes (%s in cmd is replaced by block hash)
-walletnotify= Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)
-alertnotify= Execute command when a relevant alert is received (%s in cmd is replaced by message)
-upgradewallet Upgrade wallet to latest format
-keypool= Set key pool size to (default: 100)
-rescan Rescan the block chain for missing wallet transactions
-addtag= Add a tag to your coinbase
-salvagewallet Attempt to recover private keys from a corrupt wallet.dat
-checkblocks= How many blocks to check at startup (default: 288, 0 = all)
-checklevel= How thorough the block verification is (0-4, default: 3)
-txindex Maintain a full transaction index (default: 0)
-loadblock= Imports blocks from external blk000??.dat file
-reindex Rebuild block chain index from current blk000??.dat files
-par= Set the number of script verification threads (up to 16, 0 = auto, <0 = leave that many cores free, default: 0)