I don't think so.  Unless you have personally informed outsiders of qhat your screen handle is.  Or if your handle actually contains some hint as to your real name, and someone you know is also a member,  You may want to post this question on the "Policy" board to obtain a re3sponse from the TER Staff.

LE: Probably.  It depends on how much logging TER does and if LE can get a warrant for the logs.  If they log IP addresses and LE can get the logs, then it's pretty simple for LE to get what IP you logged in from.  From there, they ask your ISP who's account used that IP at that time.  From there they can find you.

NonLE: Probably not.  You'd need access to the information within TER, which isn't easy for most people to get.  Though there's several "social engineering" approaches someone might try (bribery,  trying to get you to reply with a non-TER email address, etc).

Had it happen to me.  Some providers can figure it out, based on your discussions with them, timing, when you post etc.  My suggestion, use another alias.