Should Agassi be stripped of his Grand Slam titles?

Should Agassi be stripped of his Grand Slam Titles ? The question is currently raised by many tennis lovers, from plain amateurs to top-level stakeholders. French former pro Jean-Louis Haillet was one on the first commentators who backed up this retroactive form of punishment. He argued that Grand Slam runners-up who lost to Agassi were cheated and should now get back what was stolen from them (including Frenchman Arnaud Clément, who lost to Andre Agassi in AO 2001).

For such a point to be acceptable,  we have to agree on three things :

- Firstly : the timeline of Agassi's confessed drug-taking has to match that of his Grand Slam victories. Agassi admitted taking crystal meth in the year 1997 and speed as a fledgling tennis player, prior to 1986. These two periods do not match the timeline of Agassi's Grand Slam victories (1992, 1994, 1995, then 1999, 2000, 2001, 2003). Especially considering the 1995-1999 Grand Slam gap.

Let's say suspicion now dwells on Agassi's legitimate GS victories : are speculations enough grounds to strip Agassi  of his Grand Slams ?

- Secondly : according to tennis regulation, using crystal meth is cheating. It's a fact. But assuming Agassi took crystal meth over many years, can a prolonged use of this drug keep enhancing performances ? What are the addiction mechanisms and secondary effects of this substance ?

- Thirdly : why not, after all, taking a radical course of action and rewrite tennis history. Just to set an example and make things straight... Creating this precedent, it becomes necessary to go back in time and investigate other cases involving former players  :

• John McEnroe admitted he received steroïds "as painkillers"  (prednisone) for 6 years, claiming that he was unaware of the real nature of these drugs. Still, steroïds are classified as very powerful performance-enhancing drugs. Should McEnroe be provisionnally stripped of his GS crowns ?

• Late Australian Open champion Vitas Gerulatis admitted receiving treatment for drug-abuse (cocaïne) in the early 1980's. He died in 1994.  

• 1987 Wimbledon champion Pat Cash revealed that he used marijuana and later cocaïne and ecstasy  in his dramatic autobiography (along with a long-lasting depression).
  
  
• 1983 French Open champion Yannick Noah declared in 1981 he smoked marijuana before matches. 

What course of actions should be taken against these four high-profile tennis players ?

As a matter of fact, Agassi's drug use hides many unsolved cases in tennis. It'd be only fair for him to share responsability with some of his peers.

References
Jean-Louis Haillet : "He should be stripped of GS titles" : http://www.rmc.fr/edito/sport/93094/haillet-on-devrait-lui-retirer-des-titres-du-grand-chelem/
McEnroe and Steroïds : http://sports.espn.go.com/sports/tennis/news/story?id=1708773
Gerulaitis and cocaïne : http://www.britannica.com/EBchecked/topic/231926/Vitas-Gerulaitis
Cash, Noah about marijuana and drugs : http://www.theage.com.au/articles/2002/06/19/1023864457481.html