I just posted about a recent Washington AG settlement with a company engaging in likejacking here:

Likejacking is still an issue. The BBB referenced this article about ways to prevent it:
Avoid Likejacking Scams in Facebook

In addition to the solutions mentioned in that article, you could of course log off of FaceBook. And apparently
Apple iOS devices aren't susceptible to likejacking, because they put FaceBook into its own area.

Here's a video showing one way likejacking is accomplished: