I more or less ignore them because as you said their computer told them to. However I don’t feel any malice toward them; it’s better than nothing at all.
Ha! That’s awesome.
I wait until the end-ish of the day and say “thanks for the birthday wishes!” or somesuch.
I pulled my Birthday out of my profile too so it’s not been visible the last few years. A few friends post on my wall but, and I know this is probably a social faux pas, I pretty much ignore all the birthday posts. I don’t even say thanks at the end of the day.
Usually I’ll have a party nearby and those same friends that knew it was my birthday will be there and of course I thank them then - but I thank them for real wishes, not facebook posts.
This, this, and this. 
Or REMINDED them to.
I get tons of birthday reminders from Facebook, but only send out wishes for a select few–those I care most about.
As to the thread question, I send out a generic “Thanks to all for the birthday wishes” but only respond to those who show genuine interest and creativity. My favorite little cousin, for instance, always creates a Skald-centric gif that’s appropriate to my (and her) personality; so does my work wife. Those get special acknowledgement–not as a comment on the post, but on their Wall (okay, newsfeed).
Hey, noticed it was your birthday! Sorry I’m a day late, but “Happy birthday!”
Thank you for all of the birthday wishes. I appreciated each and every one of them and feel extremely blessed to call you all my friends.
You and 22 others like this.
I’m likewise impersonal.
Hey, we share a birthday, so a happy one to you!
And yeah, I post on my wall the day after (today) thanking everyone. I do go through and read them all, and will “like” ones that are more personal/involved than a simple “happy birthday,” to let those people know that I did actually read what they wrote.
Belated Happy Birthday!
Back to post though, Facebook is all buggy; not every birthday pops up. I played 1-2 games way back when & Facebook has never worked right since.
I “like” each post and give a generic thanks at the end of the day.
My birthday was last week and I did exactly the same thing.
I comment on each post and thank each person who took a moment out of their day to wish me a happy birthday. It’s once a year and I love the attention, so I like to acknowledge everyone individually. At the end of the day I give a recap of what we did to celebrate and again thank everyone who sent a greeting.
I like them all and thank at the end of the day. And I appreciate every single birthday greeting. I think it’s a bit of kindness to take out a little time for birthday wishes for friends and every single one of them makes me smile. So why wouldn’t I offer thanks and “likes”?
I don’t list my birthday because I don’t want ‘birthday wishes’. I don’t care if anyone I wish a hbd to on their wall responds to me personally, impersonally, or at all. I don’t think most people expect a ‘like’ or a personal response because not only do most people get a ton of these posts but Facebook also blocks them together so you don’t get notifications, etc.
I ignore them completely… and recently I hid my birth date on my profile to avoid the empty meaningless “happy birthday” wishes.
I list nothing personal on my Facebook profile so I never get birthday greetings.
I respond to about 1% of the posts of my friends on Facebook including - birthdays, births, deaths, achievements, disasters, successes, failures, starts and ends - according to the quality of the posts. I am pretty generous.
I like each comment, thank each individually, and then thank everyone at the end of the day. Even if they only do it because Facebook told them to, they still stopped for a small fraction of their day to think of me.