if by any past evidence shows, no american has freedom of speech or even privacy, this includes any american company like twitter, the snowden files should show you that amongst others.
Using Linux doesn't protect you or your friends as much as people try to make out, think of Linux as a very capable virus carrier, it wont have effects but can give it to anybody else just fine.
The better Anti Virus programs would be eastern European ones, the teams that intercept Virii from Russia and China first geologically.
Two examples would be Kaspersky Internet Security and Eset NOD32/Smart Security, First having HQ in Moscow and second been in Bratislava Slovak Republic, These companies are in the right place to get detections early and swiftly and show in their comparative results as been two of the best out there.
Also, you're not protected against a lot of zero day infections, and need good pro-active heuristic sandbox anti virus features, which most will have now, just look for ones which offer it on active scanning.
RE: Musk backed OUT on the Twitter deal
Think you mean people like Tom Mueller