It is literally GPT4. This is not the similarly named open source LLM "GPT4All."

GPT4Free is an API reverse engineering and proxy project which exposes an API to use GPT4 by proxy through GPT4 based services like the search engine Phind.

Essentially you are using the reverse engineered services OpenAI credits to access GPT4 instead of using your own OpenAI account.

Then these services need to model their threats with more sophistication. The existence of this project indicates there are security vulnerabilities in services that use OpenAI. In any case, I maintain that increased attention to this topic is a good thing rather than a bad thing, which is contrary to what GGP was suggesting when they referenced the Streisand effect.