Tabs VS Spaces

Which do you prefer in your code?
Personally I like tabs more but they're misused for formatting instead of indentation by many which is annoying and kind of defeats the purpose.

#include <stdio.h>
#include <string.h>
int main(int argc, char *argv[]){int i;size_t arg_len;for(i=0,arg_len=0;i<argc;++i){
printf("%i: %s\n",i,argv[i]);arg_len+= strlen(argv[i]);}printf("Length of arguments: %zu\n",arg_len);return 0;}

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