Is it haram for girls to post their pics on the internet without hijab?

Occasionally, it is seen that some Muslim girls/women post their images on different internet websites **without veil (hijab)**. Based on Islam, it is Haram (forbidden) for women to expose their bodies and their beauties for strangers as non-mahram(s); and factually only Mahrams can see their hairs. Accordingly, would it be haram to do it in some parts of virtual world such as Internet, which is full of non-mahrams there?