http://decision.tcc-cci.gc.ca/tcc-cci/decisions/en/item/66928/index.do 
Martin v. The Queen (February 19, 2014 – 2014 TCC 57) is an interesting example of one of the rare cases in which the Tax Court essentially determines that an appellant is a vexatious litigant and curtails their access to the processes of the court. The background was typically odd:
[1] The Court has before it five motions filed by the appellant and a motion to quash the subpoena addressed to Claude Prévost.
[2] The appellant is appealing from the determination of a loss. It is not entirely clear what the nature of the loss is, but it appears to be a capital loss of more than $14,000,000 related to the loss of his clients. At times, the appellant also seemed to be expecting other outcomes that are not under the Court’s jurisdiction.
[3] If a party wishes to examine an individual other than a party, it must receive prior authorization from the Court. This is in accordance with Rule 99 of the Tax Court of Canada Rules (General Procedure).
[4] Absent such an order, a third party is under no obligation to answer the party’s questions.
[5] The appellant did not obtain an order under Rule 99, but sent written questions to five individuals who are not parties.
[6] The five individuals in question did not respond and the appellant filed motions for the Court to order:
(a) the arrest of these five individuals;
(b) the detention of these five individuals until they answer the written questions.
[7] The appellant did not convince me that there is any basis to these motions.
[8] The five individuals had no obligation to answer the questions the appellant had sent.
[9] As a result, the five motions are dismissed.
The subpoena purportedly issued in support of the motions was quashed.
The appellant had been involved in similar prior proceedings before the Tax Court. In light of all the circumstances the Court determined to limit his access to the Court’s processes:
[20] As a result, considering the Court’s inherent power to control its process, it orders the following, of its own initiative and for the purpose of avoiding unnecessary proceedings:
(a) In this proceeding:
(i) the appellant shall obtain the Court’s authorization prior to filing new motions;
(ii) the appellant shall obtain the Court’s authorization prior to obtaining a subpoena to summon an individual to appear at the hearing of a motion.
(b) With regard to the hearing on the merits, the appellant shall obtain the Court’s prior authorization if he wishes to serve a subpoena on Claude Prévost, to Quebec’s Deputy Minister of Finance and the Economy or to the Commissioner of the Canada Revenue Agency.