Chelsea and Barcelona find themselves paired together in another Champions League semi-final. We all remember what happened last time, right?

The popular narrative is that Chelsea were denied between four and six penalties by Norwegian referee Tom Henning Ovrebo. On Thursday, Ovrebo told The Guardian newspaper that he still receives abuse about that night.

It [abuse] has lasted and I get about three to four emails [from Chelsea fans] a year. It is not nice but nothing too serious, either. I don't let it upset me or my family. They do not know much about it, as I do not show them the emails.

As reprehensible as it is to still be abusing an official for a match so far in the past, Chelsea fans have good reason for their outrage. Ovrebo admits as much:

Looking back, there are certainly things I would have done differently. I learnt a lot from that experience. But all referees will tell you that they have good and bad matches, moments they do well and moments they do not so well. That is all part of the job.

But just how much of the outrage is justified? Were all the penalty claims legitimate? Here's a recap of the moments that made Chelsea players, staff and fans scream bloody murder and whether they had a legitimate case.

1) Did Dani Alves Body-Check Florent Malouda?

In the 23rd minute, Florent Malouda broke free down the left side. Dani Alves closed as Malouda hit the intersection of the endline and the area. The Chelsea man cut the ball back and collapsed on contact with Alves.

Ovrebo blew for the foul, but placed it just outside the area.

Analysis: Alves did indeed foul Malouda two yards outside the area. Malouda kept the ball on that foul and pushed into the area where he cut back.

On Malouda's move, Alves did what defenders have done since the beginning of time and looked to turn in the direction that would obstruct the attacker to the maximum degree possible. If he hadn't used his arms, I would say it was fair.

However, the Brazilian held Malouda with both arms as he turned. Malouda realized the ball was lost to a retreating Yaya Toure and flopped ridiculously, but he should have had the penalty anyway.

Verdict: Incorrect Decision, Penalty

2) Did Eric Abidal Pull Didier Drogba to the Ground?

Just a few minutes later, Didier Drogba brought a long ball down as he broke in behind the Barcelona defense. As Drogba entered the area, Eric Abidal caught him from behind and clashed for the ball. Drogba went down and Victor Valdes smothered the chance.

Ovrebo's whistle remained silent.

Analysis: Abidal did indeed pull Drogba's shirt. That much is clear. Whether he also tripped him is much less certain. It is also clear that Drogba was not going down until he realized that Valdes was going to beat him to the ball.

By the standards of referee Bjorn Kuipers (who officiated Barcelona's match with AC Milan this week), the incident would be a clear penalty. By the standard of most referees, not so much.

Verdict: Correct Decision

3) Did Yaya Toure Come Through the Back of Didier Drogba?

In the 55th minute, Didier Drogba and Yaya Toure wrestled for possession before Drogba broke into the top of the box. Toure's sliding tackle took both the ball and Drogba, eliminating the chance.

Ovrebo saw nothing wrong with the challenge.

Analysis: Toure did come in from behind, which is always a dangerous thing for a defender to do. However, a slide tackle from behind can be executed legally, and Toure did just that. He came in cleanly and took the ball before making contact with Drogba.

Verdict: Correct Decision, and Drogba should have gotten a yellow card for his reaction

4) Did Yaya Toure Pull Down Nicolas Anelka?

The game was nearing the 80th minute when Nicolas Anelka chased a ball down the left side of the area with Yaya Toure in hot pursuit. As the two chased, Anelka went down.

Nothing from Ovrebo.

Analysis: Just no. By far the weakest of Chelsea's penalty claims from the match.

Verdict: Correct Decision

5) Did Gerard Pique Handle the Ball in the Area?

Just three minutes later, Anelka again threatened with a neat little flick that seemed destined to put him in free on goal. But the ball struck Gerard Pique's right hand and Barca were able to clear.

Ovrebo was silent.

Analysis: Pique's handball was the clearest penalty of the night. Anelka's touch was sublime, he would have rounded the defender and been free 1-on-1 with Valdes. Pique's arm was up in a position his movement did not demand. Clear infraction.

Verdict: Incorrect Decision, Clear Penalty

6) Did Samuel Eto'o Block Michael Ballack's Shot with His Arm?

In the dying moments of added time with Chelsea trying to save their Champions League life, they played a corner kick. The ball was headed up in the center and dropped to an unmarked Michael Ballack on the back side. The German stuck the ball beautifully on a full volley only to see it blocked by the back and left arm of Samuel Eto'o.

Ovrebo saw nothing wrong

Analysis: In certain circumstances there is nothing wrong with a shot from point-blank range hitting a defender's arm. But Eto'o threw his left arm over his head in a clear attempt to make sure it didn't make it to goal. He could make an argument that he was protecting his face, but it would still be a penalty.

Verdict: Incorrect Decision, Penalty

Final Tally

It is clear that Ovrebo blew this game. Although not quite as bad as Chelsea fans like to think, he was plenty bad enough to cost the Blues a trip to the Champions League finals.

As Chelsea and Barcelona prepare for their upcoming semi-final rematch, fans of both teams will hope that the referee stays firmly where he belongs...in the background.