Millions of smart TVs from Samsung and some streaming devices from Roku recently were found to be vulnerable to cyberattacks, allowing intruders to take control and remotely change channels and volume settings, among other things, according to Consumer Reports research. Vulnerabilities were discovered not only in Samsung televisions, but also in TVs from TCL and other brands that sell sets compatible with the Roku TV smart-TV platform and streaming video devices such as Roku Ultra, according to the report.