Tisha Be'Av can be a trying day (as it is meant to be), as we recall the חורבן, mourn the בית המקדש, and hopefully do תשובה, with the help of the chamisha inuyim, in which we abstain from certain regular, normally permitted pleasures and conveniences.
So many people desperately want to flip it to a happy day. As the posuk says in Zecharya, in a prophecy of the future, that צום הרביעי וצום החמישי וצום השביעי וצום העשירי יהיה לבית יהודה לששון ולשמחה ולמעדים טובים.
But we need to know how to hopefully do that. And the way is by getting the message of Tisha Be'Av, not by rebelling against it.
I recently saw a story online about a Chasidic leader "canceling" Tisha B'Av".
It is also known that there is a custom among some Chasidim (and maybe a bit among some others too) to throw things on Tisha Be'Av in Shul (h/t). In the Chabad-Lubavitch faith, people bring acorns, dried beans, peas, or so, to throw at each other during Eicha, presumably at other times during 9 Av services as well (sources: 1 - See Heads up: section, paragraph two, at Ari Teman - JusticeForAri.org on Twitter: "@Tuviae @DBashIdeas Chassidim take seriously that the Torah should be approached and appreciated with joy. That laughter is not disrespectful, but an appreciation of the Torah and how this man is teaching it as he reads it (which is the point, and why the Temanim, for example, still do…" / X, 2 - see comment "Tishabav" here).
And a neo-Chasidic leader tells a story about a Rebbe who danced on Tisha Be'Av.
And truthfully, I understand where such behavior comes from (although strongly rejecting it), since the atmosphere can get quite heavy. But, if we understand the true observance and message of Tisha Be'Av, which includes ways and paths leading to a brighter future, we should be able to keep things in perspective, and not resort to foolishness and frivolity on such an important day.
As we are taught by Chazal, כל המתאבל על ירושלים זוכה ורואה בשמחתה, properly mourning ירושלים of old leads to the joy of its rebuilding.
May we merit seeing that soon.
A healthy (spiritually and physically) and successful Tisha Be'Av to כלל ישראל.