1. Russia has been accused of this before, notably when hackers attempted to hijack an election in neighboring Ukraine in 2014.

2. Others then used it to hijack the site before Twitter programmers could fix the problem.

3. I was hoping that it was a hijack because then there will be a big hope that my son is safe.

4. Internet socket interception, which allows a malicious app to hijack the flow of traffic to an app.

5. Indian airports are on high alert after local intelligence reports warned security officials of a possible attempt to hijack an Indian airliner.