Hi and Welcome. My Name is ***** ***** I look forward to assisting you today with your question.
Is your entire phone locked up or just the internet/chrome browser ?
That is a SCAM message. We can clear it. Go to Settings > Applications Manager (or Settings > Applications > Application Manager)
Swipe left or right to All tab which is next to Installed, Running etc tabs.
Find and select Internet/Browser. Tap Clear Data. Then go back select Chrome do the same for Chrome app or all the internet apps that are affected. That will clear it.
If you are unable to access Settings or if your entire phone is locked up, please let me know
Please let me know if that didn't work, so we can continue troubleshooting.