Time travel is used to be one of the themes of Sci-Fi novel and movies. But nowadays, some leading researchers in physics believe the possibility of time travel at least in a theoretical way.
If there are time travelers, some of them must live in the modern world. There are enormous travelers, since they can go back as much as they want to. Then, how can you detect one of them?
This is a typical problem often described only in fiction. However, one of the researchers conducted a survey seriously. This is the academic article.
Cornell University Library: Searching the Internet for evidence of time travelers
The author tried to detect some evidence of time travelers using the internet. He searched the internet comprehensively to find some footprints which could not be written by an ordinary person. He chose the words "Pope Francis" and "Comet ISON", since they are defined just recent. He hypothesized that only time travelers could mention about these words before their establishment.
Unfortunately, and expectedly, this attempt resulted in failure. No meaningful description was found. The author comments that this result does not mean the absence of time traveler. I agree with it.
I appreciate such an ambitious experiment. To be honest, however, this research is not well constructed. If there were some time travelers, they could erase their descriptions before they are discovered by the researcher. The author had to catch the evidence of such a replacement. OF course it is fundamentally impossible.
By the way, it is notable that the author selected Twitter as a material of comprehensive search. Twitter preserves all logs of the users. Their timestamps are hardly disguised. This characteristic will be available in a different way. For example, Twitter can prove that someone began to use an original term faster than any other persons. It is also interesting.