I don't think so. However , if you are planning on doing an explosion in an area and you drew the plan and the date and everything , the police can arrest you. Talking is normal but serious talks can get you in trouble.
My friend kept getting messages from a guy saying he was going to beat her, burn her house down ,rape her, ect although he never did followed through he got taken and locked up for that. So yes.. It is
Talking about doing a crime, may be not. Planning a crime, Yes, of course! What's the police for anyway? It is to PROTECT a crime from happening. They won't let you do it first then get on the court thing then. It would be stupid!
Just talking about it is not a crime. However, planning by more than one person that is accompanied by any concrete steps to carry it out, such as obtaining disguises, casing a target, obtaining weapons, etc. is "conspiracy." And any physical attempt to carry it out, even if you change your mind and walk away, can be "attempt."