I might be in the minority, I don't know, but I want the runner to use Planned Attack to Siphon me. Or at least, make the attempt to.
They can't run to face-check my ice, install any breakers, or do anything else if they have to click away those tags. I run cards in each corp deck meant to punish tag-me runners for their hubris, so much of the time I can Closed Accounts them (or even, heart of the cards willing, Scorch them) and make sure that nobody's walking away happy (least of all them).
It lessens the swing of the Siphon by 2, eats an extra click, and helps me decide where to put the ETR Ice. It also isn't a good way to Siphon turn 1, for Criminals especially. What it's going to do that I'm not looking forward to is Criminal use of other run events, like Demo Run or Indexing or other 1-of out-of-faction things, and non-Criminal reliability of Siphon increasing.
Even then, though, I still won't worry about it turn 1 nearly so much, most of the time, if they have to Planned Attack their way to it. It hurts them quite heavily -- and if they hold off even one or two turns, most of my decks ought to be in a decent position to deal with future Siphonings (though that's obviously never a guarantee).
EDIT: It's annoying, for sure, but I don't think that Siphon is a big threat with PA. If it is, it's because now I need to cover both R&D and HQ on turn one to prevent them picking Indexing/Siphon based on what I leave open.