Facebook poke - Facebook Apps

I would assume no. Rather than asking fixya, you should be asking Facebook customer support.

To poke someone:

1. Go to your friend's timeline, who you want to poke
2. Click the '...' icon at the bottom right of their cover photo (the button to the right of 'Message')
3. Select Poke

he or she is poke you back

Here there is a solution

http://www.facebook.com/help/136465059824353/

if

1. You didn't use your real name. Facebook will find you and spit you out.
2. You joined too many groups. (The maximum limit is 200 groups per user.)
3. You posted too many messages on a wall or in a group. E.g. Guy Kawasaki had his account disabled-in his case for "excessive evangelism."
4. You posted in too many groups, too many user's walls. (That's what spammers do, silly.)
5. You friended too many people. (Not so long ago this was a prime cause of disabled accounts, but Facebook has instituted a maximum of 5000 friends that should protect you from yourself.)
6. Your school/organization affiliation is doubtful.
7. You're poking too many people. (Beware the odd FB app that pokes on your behalf.)
8. You advertised your app on wall posts.
9. You used duplicate text in multiple messages.
10. You are a cow, dog, or library.
11. You are under 18 years old and not part of a High School group.
12. You wrote offensive content.
13. You scraped information off Facebook. E.g. Facebook bots disabled Robert Scoble's account.

for Reactivation
http://m.facebook.com/c.php?id=502139307&code=673854461

sign out and sign back in, if that doesnt work. try to download the newest adobe, or java...or maybe your computer doesnt like poking people

install latest java engine

facebook is banned in some countries like pakistan ,saudi arabia

Are you sure it's not there. When you're logged in under your name, it won't show the "Poke". Have you tried logging in under someone else's name? There is no way to "hide" or "unhide" this feature on Facebook, so it should be there if you look at your profile from another's account.