It is governed by the SANRAL act, there own law (which in parts dates back to before the ANC)
There falls under criminal law section, ie. it is like stealing or murder. There is no EULA for you to agree to the law
I am referring to this:
http://www.sanral.co.za/e-toll/app/...ocuments/e-toll_TermsAndConditions.pdf?id=123
Currently you cannot get an e-tag without agreeing to this.
http://www.sanral.co.za/e-toll/app/gort_xml/files/content/documents/e-toll_InformationForm_EN.pdf - please look at General Communication, section b.
