Seriously. Why not, "Lamaar Smith tried to Destroy the Internet." Hyperbole, sure, but it's a billboard.
If you want something like this to be effective, you have to take your inspiration from political attack ads. Throw his desaturated face up there on a black background.
Completely agree with your assessment on taking a more "shocking" approach, and also with the original comment that many do not know that SOPA and Lamar Smith are connected some how.
It think they are using the current phrase as a parody of the famous anti-litter ad campaign "Don't Mess With Texas" [1]
As a Texan who happens to live in Lamar Smith's district, I think the effectiveness is entirely dependent on where in his district it is bought. His district includes SW Austin and many rural areas such as Kerrville.
Edit:
for some reason the wikipedia page is not linking correctly to wikipedia. using google search
If you want something like this to be effective, you have to take your inspiration from political attack ads. Throw his desaturated face up there on a black background.