Neither CEA nor EVF own the trademark “Effective Altruism”, and we do not attempt or intend to control other people using the phrase.
We do own trademarks for “Centre for Effective Altruism”, “Effective Altruism Global” and the heartbulb logo. As owners of prominent EA products such as EA Global and EffectiveAltruism.org, CEA does consider itself among the stewards of the EA brand, but not its owner. There are many organisations and individuals whose use of the phrase “EA” (and their associated activities) contribute to the overall EA brand, and we think that’s appropriate.
I’m sorry to hear you’ve had these negative experiences.
At CEA, trial tasks (minutes or hours) and work trials (days) are key components of our typical hiring rounds because we believe them to be better predictors of performance in the role than other assessments such as resumes or interviews. We do, however, always offer to compensate candidates for their time for any longer trial tasks and work trials if it's legally possible. (Visa rules mean this is sometimes not possible for candidates who travel, e.g. to the UK, for a trial without a work visa.)
Addendum: we have in rare instances attempted to prevent people acting in ways antithetical to EA principles from identifying themselves with EA (example), but it remains the case that we do not generally do this among members of the community acting in good faith.