Enacted into law in 2009, here's the complete Texas 'Online Impersonation' statute. In key part:
"Sec. 33.07. ONLINE IMPERSONATION. (a) A person commits an offense if the person, without obtaining the other person's consent and with the intent to harm, defraud, intimidate, or threaten any person, uses the name or persona of another person to:
(1) create a web page on a commercial social networking site or other Internet website; or
(2) post or send one or more messages on or through a commercial social networking site or other Internet website, other than on or through an electronic mail program or message board program.
(b) A person commits an offense if the person sends an electronic mail, instant message, text message, or similar communication that references a name, domain address, phone number, or other item of identifying information belonging to any person:
(1) without obtaining the other person's consent;
(2) with the intent to cause a recipient of the communication to reasonably believe that the other person authorized or transmitted the communication; and
(3) with the intent to harm or defraud any person.
(c) An offense under Subsection (a) is a felony of the third degree. An offense under Subsection (b) is a Class A misdemeanor, except that the offense is a felony of the third degree if the actor commits the offense with the intent to solicit a response by emergency personnel."
Following the letter of this law, there may be a lot of criminals. "Harm" can be very broadly construed–one person's joke is another person's harm. This New York Times article about online Texas political shenanigans might identify some third degree felony law breakers.
I'm not sure how many actual Texas prosecutions have come from this law. A case out of Austin was dismissed because the person accused of the crime was from Cincinnati.
I am aware of someone who wasn't prosecuted for this but was threatened with prosecution, and experienced significant harm in his personal life relating to a parody Twitter account. Seems to me that there are some First Amendment concerns with a broadly written law that makes this a third degree felony.
The more you know….