Searching the Internet for evidence of time travelers
Isn't the issue here that they are describing the methods through which they are trying to determine time travel. In effect, telling anyone in the future exactly what not to do.<p>Let's also assume that somebody had a reason to travel into the past, say to kill Hitler. Our timeline would record that an Austrian artist was murdered in the 1920s. We would not consider this historically significant.<p>I think time travel is inherently very difficult to detect. Even if a time traveller 'dropped' tech. This tech would be recoverable by popping back in time and recovering it.