A rep for Levi Johnston, the young man best known as the father of former Alaskan governor Sarah Palin’s grandchild, has released a statement to Twitter in the wake of a sketch on last night’s Tonight Show with Conan O’Brien in which actor William Shatner read a series of tweets attributed to Johnston as spoken-word poetry.

The text of the statement, obtained by Entertainment Tonight: “My client, Levi Johnston, is being impersonated on your media (Twitter) and this is leading to libel and slanderous statements being attributed to him. … We want you to put an immediate end to this illegal activity. … You are being used as a medium to promote this illegality and we want immediate action. … You are now on notice and must take steps to put an end to what is clearly against the law and against your policy. … We want to know what steps you will be taking to correct what is clearly a problem which is escalating.”

According to the Huffington Post, Johnston’s attorney has also asked NBC to retract the sketch. When contacted by EW, a spokesman for the Tonight Show had no official comment.