Like search your computer? They'd have to take your computer. Then it would take immense manpower to go through it efficiently. Just seems unlikely. USA had a similar issue with copyrighted material. Their solution is not a solution. It's more of a mitigation. They

• scan your internet usage (mostly through DNS). This is easy for a country where the country controls the utilities
• block websites through the ISP

All of these things can be overcome with VPN or tor network, but that's why it's a mitigation and not a solution