PHP function Mt_rand, Rand and other generated random number can be predicted??

PHP function Mt_rand, Rand and other generated random number can be predicted??

Please ask:
Because recently to do a one-dollar capture of the function, see the network: for example, Ecshop inside the one dollar treasure plug-in, he is and the old always color and user-related data to calculate the lucky number.

But if a function like Mb_rand is random enough (that is, almost impossible to predict), why not use random functions such as mb_rand to generate a lucky number?? Instead, it takes a lot of trouble to pick up the data and go to all kinds of calculations.

If I use the Mb_rand function to generate the lucky number, the fairness does not (afraid that the random function generated by the random number will be predicted, and then encountered some advanced players, randomly fiddle some numbers, to predict, it is unfair)??

