Has the TestNet ever been reset? The Bitcoin TestNet is a network identical to Bitcoin in every respect except that the bitcoins on it are worthless because no one accepts them in payment or values them for anything other than testing purposes.  In essence, TestNet btc are valuable because they are worthless, allowing for useful experimentation when developing.

I read somewhere that one way the TestNet can be prevented from acquiring significant value and mining power is by being reset from time to time so that TestNet btc remain easy to mine and acquire for testing purposes.  This made me curious--has this ever happened before?
The current testnet is on its third iteration, somewhat unimaginatively titled testnet3.

It was put that way by this commit:


  Testnet, Mark III  
  
  gavinandresen authored 2012-04-12


Before that, we had testnet2: (though we didn't call it that back then)


  Reset testnet with a new genesis block  
  
  davout authored 2011-02-03


Before that, testnet:


  Gavin's TEST network as -testnet switch, misc fixes
  git-svn-id: https://bitcoin.svn.sourceforge.net/svnroot/bitcoin/trunk@168 1a98c847-1fd6-4fd8-948a-caf3550aa51b
  
  s_nakamoto authored 2010-10-19


Man, sourceforge. Brings ya back, doesn't it?

Essentially, the devs want testnet coins to be worthless for two reasons:


to make them easy to mine
because it's nice to have a place to demonstrate attacks against bitcoin without actually disrupting the network. You can show that an attack is valid without costing people real money.


Now that I think of it, we're due for a new testnet soon. Sell those testnet coins!