Yes, there are some very strong othello programs. The Moor beat world champion in 1980 and since then programmes have been able to match human world championship level players. In 1997 program called Logistello did beat the current world champion Murakami 6-0 in six matches. Of course using such programs is considered cheating and it is prohibited in BK user agreement.

Surely it is quite hard to know if someone is using such program or if he/she is just a very good player. Personally, i don't even bother thinking about that. If someone chooces to use such tools, they're only fooling themselves. It doesn't take anything away from me as i'm not obsessed with ratings and stats. I still enjoy my games no matter whom i play against.

If you suspect someone is using such programs, try talking to them about the game. There might be something fishy if someone plays like a pro but cannot explain the moves. Also try playing them in 6x6 or 10x10 as programs for those are not quite as strong as the regular 8x8 ones. At least i'm not aware of such programs.

In my opinion, even if you think you have a strong case about someone being a cheat, it is not worth to go public with your accusations. It just causes bad feelings, flamewars and such. And the accusations could be false, it's not a easy task to prove someone cheats. If you think someone does cheat and you're bothered about it, just don't play against him/her anymore.