I know the odds of someone "cracking" your private key are astronomical, but you know that there are high end computers that all they are doing is coming up with private keys, you randomly guess tens of thousands per second, it wouldnt take long to find at least a few that would match..
Almost like playing a lottery right?
I've put a lot of thought into this and I created a script that was generating 20,000 keys per minute and stored the key pairs into a database.
The bigger issue I ran into was checking those addresses for a balance, that was much slower around 40 addresses per minute, since it was over the internet and had to check it against the blockchain. The next HUGE issue was space. In just 14 hours I had over 15 GB of data storing ~20 million key pairs. The storage and checking these keys is a huge issue when trying to get lucky with a private key.
At this point I stopped and I did the math: if I had unlimited storage space and kept running the script for one year I would only generate 10 billion key pairs taking up 10TB of data, this is out of the 1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976 possible keys.