Tried, I would say it depends of the age group. But "tried once in your life" is not the most important for prohibition issues, it's people using it regularly the real issue.

So, do it regularly (at least once a year) ? It's hard to find stats on filesharing usage, but the data I remember is about 1/3 of people with internet access using p2p, which is about 2/3 of the population, so 2/9 = 22%, nearly twice the 13% who used cannabis "once per year". Cannabis is not the only durg, but p2p isn't the only form of filesharing, so it more or less compensates.

Is that your real question? It feels like you're objecting to something else or asking an entirely different question, like, say, "Does filesharing really deserve the 'prohibition' connotations more than drugs?".