Based on your question, it appears that you are talking about a teacher at a school other than the one your son attends. Assuming that is the case, if the school is in the same school district as yours you can file a grievance pursuant to policy FNG of the school district's board of trustees. Since this is a race issue, you may also contact the Office of Civil Rights at the US Department of Education. You can also file a report with the Texas Education Agency. Other than that, at this moment there is not anything else you can. If the situation persists, then you may want to talk to a lawyer about invasion of privacy and possible cyber-crimes.
This is general information and should not be construed as legal advice. Without knowing the specifics of your situation and engaging in an attorney-client relationship I am unable to provide specific direction.