There can certainly be coercion even in countries that maintain secret ballots. In Russian regions, it is not unheard of for civil servants and teachers to be told by their superiors that they must vote the favoured party “or else”, and a mobile phone picture of their ballot might be demanded as proof that they did so.
If I am able enough to tweak my stuff to take such a picture I'd be surely able enough to provide a fake picture. The attacker would need to provide the device which in turn does not scale very well. So, apart form husbands, this attack would not make much sense.
If that was to be done in scale, it'd be noticed fast. And people would ask questions quickly. That might be different for Russia, I admit. In US, no need for all that, you have electronic voting boxes, which are completely opaque to voters and counters.
EDIT: spelling.
whatever increasingly convoluted suggestion you'll make next probably doesn't work either.
I also don't appreciate your arrogance in trying to shut down this discussion pre-emptively. Maybe try listening more in the future, you might discover interesting things even if they don't agree with your pre-set ideas.
There are ways to avoid being coerced when enabling online vote: have an online vote for a week, then a few days after the online vote ends, have one day of paper voting. If you were coerced during the online vote, you can still go to the paper vote later, at which point your online vote will be overwritten by the paper vote[0]. This is still not fool proof (i.e. one can force people not to go to the paper vote after coercing their online vote) but as explained above, neither is normal voting.
It's like open source software. I am not able to check everything I use. But there are parts where I am capable enough to do so. For the rest I rely on others to do so.
You can't run a society without trust. It's about the ability to verify or have persons you trust to verify for you.