I can give you an example here. We had to do some basic local VAT validation for EU countries and as the API that you can use for that has some issues for some countries (as it checks this in the national databases) we wanted to also have a basic local one. So using Claude 3.7 I wanted to get some basic VAT validation, in general the answer and solution was good, you would be impressed, but here comes the fun part. The basic solution was just some regular expressions and then it went further on its own and created specific validations for certain countries. These validations were something like credit card number validations, sums, check digits, quite nice you would say. But the thing is in a lot of these countries these numbers are basically assigned randomly and have no algorithm, so it went on to hallucinate some validations that don't exist providing a solution that looks nice, but basically it doesn't work in most cases.

Then I went on github and found that it used some code written by someone in JS 7 years ago and just converted and extended it for my language, but that code was wrong and simply useless. We'll end up with people publishing exploits and various other security flaws in Github, these LLMs will get trained on that and people that have no clue what they are doing will push out code based on that. We're in for fun times ahead.