She only threatened legal action after those memes started and when her flight movements got the attention of the right in an attempt to make her less credible of a voice speaking out against trump.

And knowing how batshit insane trump cultists can be and how she's basically the single most hated person of his base I'm not surprised that she feared for her security.

Those records were public for years but the legal action only happened after someone created those memes and even fox news suddenly cared about plane emissions...