What better way to demonstrate an unsecure network than by beaming a message out of a gigantic electronic billboard.
Hackers allegedly did just that to a massive screen at Liverpool One shopping centre over the weekend.
"We suggest you improve your security. Sincerely, your friendly neighborhood hackers," the message allegedly read, according to a photo first uploaded to Reddit on Sunday.
Motherboard could not independently confirm the photo or its contents.
An unidentified person who returned a call to Liverpool One's main enquiries line repeatedly declined to elaborate on the photo or give additional comment.
"We will be giving nothing else at the moment; we'll be leaving it to our marketing department," the person told Motherboard in a phone call. Motherboard will update this piece if Liverpool One publishes a statement.
A reverse image search on both Google and TinEye returned no relevant results, suggesting that the photo is new. The website of Elonex, the apparent manufacturer of the billboard, does list Liverpool One as a customer.
A spokesperson for the Merseyside Police said they had not been informed of the alleged incident.
The message also included the hashtag #JFT96. This is a likely reference to the 96 people who died during a disaster at a Liverpool football game in 1989.
Hackers have targeted electronic billboards before. In 2015, someone made a billboard in Atlanta display the infamous Goatse meme.
Correction: Due to a typo, an earlier version of this article reported that the message included the hashtag #JFT69. It was in fact #JFT96. Motherboard regrets the error.