Maybe read the room a little before posting. My sarcasm, in this case, is very warranted, but you "correcting" me with an etymology lesson really makes you look apologetic. Why would you post something so irrelevant to the conversation?
But the wording implies that the legality of this person's situation matters for the rest of the sentence, either meaning that being illegal would justify deportation, or not being able to come back after being arrested without reason.
The wording is establishing who the subject of the post is about. Since their name wasn't mentioned and you knew who they were talking about I can see that it was super effective.
Because a major point of 'reason' that the right-wing has with this person's abduction is that he was 'here illegally so it doesn't matter what happens to him'.
This messaging isn't for you. Its mostly meant to shortcircuit the above.
These little shitty 'gotcha' purity tests the left constantly foists upon itself is tiring and the stuff of children. The man the US government abducted is likely dead; murdered by despicable people willing to do unspeakable things to meet their ends. Yet you sit here griping about, what? The way one person, trying to shout back in solidarity against the coming horror, said something slightly askew? I'd think it pathetic if it weren't so exhausting.
The person in the picture likely didn't intend it, but qualifying such a statement with "legally" does have the effect of legitimizing the fascism position both in general and regarding illegal immigrants.