Splitting question.

I have been giving another shot at online BJ at Pokerroom.com and have noticed quite a few people splitting their 20's when the dealer has a low card. A few times they have won but I have noticed that when we all lose it is due to the 20's getting split. Is there a time that you would split your 20's? I never split my 20 no matter what. Now when I see people splitting their 20's (2 face cards) I leave that table and make a note of who they are so I don't sit at their table again.

Also, quite a few have been standing on their 14 and 15 when the dealer has a ten showing. Does this have to do with card counting? But, I don't see how you can count cards accurately online.

No they can't count cards at Pokerroom.com because of simple reason that Pokerroom.com software shuffle deck after each round of betting.Those people that stand on 14 and 15 do not use correct strategy.
And also if you follow correct basic strategy, you are fine. Other players can double down on hard 20 if they want to, and it wouldn't hurt you only them in a long run.

I also saw one person hit a 20 instead of standing. I figured he hit the wrong button by mistake since I only saw this once.

I seem to do okay at this site by playing Basic strategy. You can watch the table for awhile and if it seems to be on the players side, then you can join if there's room. By doing this I have made a bit of money (not a lot). I prefer BJ to poker. Poker gets boring when people take soooo long to place a bet or call.