Question: Spanish people tend to use "x" instead of "ch" in internet language, for example:

> 
> "mandixo" = me han dicho  
> 
>  "noxe" = noche  
> 
>  "muxo" = mucho
> 
> 
> 

Why do they do that? Is it only because of save time/laziness reasons or does it have anything to do with imitating the oral language? 

Thanks for your answers.

Answer: 
The X vs CH pronunciation comes from Catalan/Valencian vs Spanish communities. In Catalonia/Valencia, for example, the infinitive form of the verb born is néixer/naixer. You can find many other examples in both communities. 

My suspicion is you met a Spanish person from Catalonia or Valencia.
Across Latin America you will not find the use of the X in that manner.
Because is faster to write and sounds similar as in English because (bcos), today (2day) ... but *x* can sometimes mean *por* as in *xq* (porque).

For More information about abbreviations we use quite often: ["xq" in Internet slang/abbreviations](https://spanish.stackexchange.com/questions/583/xq-in-internet-slang-abbreviations/594#594)